diff --git a/src/jetplot/chart_utils.py b/src/jetplot/chart_utils.py
index 6fe157d..2bf1da2 100644
--- a/src/jetplot/chart_utils.py
+++ b/src/jetplot/chart_utils.py
@@ -1,10 +1,11 @@
 """Plotting utils."""
 
-from collections.abc import Callable
 from functools import partial, wraps
+from typing import Any, Literal
 
 import numpy as np
 from matplotlib import pyplot as plt
+from matplotlib.axes import Axes
 
 __all__ = [
     "noticks",
@@ -114,14 +115,25 @@ def nospines(left=False, bottom=False, top=True, right=True, **kwargs):
     return ax
 
 
-def get_bounds(axis, ax=None):
-    if ax is None:
-        ax = plt.gca()
+def get_bounds(axis: Literal["x", "y"], ax: Axes | None = None) -> tuple[float, float]:
+    """Return the axis spine bounds for the given axis.
 
+    Parameters
+    ----------
+    axis : str
+        Axis to inspect, either ``"x"`` or ``"y"``.
+    ax : matplotlib.axes.Axes | None, optional
+        Axes object to inspect. If ``None``, the current axes are used.
 
-    Result = tuple[Callable[[], list[float]], Callable[[], list[str]], Callable[[], tuple[float, float]], str]
+    Returns
+    -------
+    tuple[float, float]
+        Lower and upper bounds of the axis spine.
+    """
+    if ax is None:
+        ax = plt.gca()
 
-    axis_map: dict[str, Result] = {
+    axis_map: dict[str, Any] = {
         "x": (ax.get_xticks, ax.get_xticklabels, ax.get_xlim, "bottom"),
         "y": (ax.get_yticks, ax.get_yticklabels, ax.get_ylim, "left"),
     }
@@ -187,14 +199,20 @@ def identity(x):
 
 
 @axwrapper
-def yclamp(y0=None, y1=None, dt=None, **kwargs):
+def yclamp(
+    y0: float | None = None,
+    y1: float | None = None,
+    dt: float | None = None,
+    **kwargs,
+) -> Axes:
+    """Clamp the y-axis to evenly spaced tick marks."""
     ax = kwargs["ax"]
 
     lims = ax.get_ylim()
     y0 = lims[0] if y0 is None else y0
     y1 = lims[1] if y1 is None else y1
 
-    ticks: list[float] = ax.get_yticks() # pyrefly: ignore
+    ticks: list[float] = ax.get_yticks()  # pyrefly: ignore
     dt = float(np.mean(np.diff(ticks))) if dt is None else float(dt)
 
     new_ticks = np.arange(dt * np.floor(y0 / dt), dt * (np.ceil(y1 / dt) + 1), dt)
@@ -206,14 +224,20 @@ def yclamp(y0=None, y1=None, dt=None, **kwargs):
 
 
 @axwrapper
-def xclamp(x0=None, x1=None, dt=None, **kwargs):
+def xclamp(
+    x0: float | None = None,
+    x1: float | None = None,
+    dt: float | None = None,
+    **kwargs,
+) -> Axes:
+    """Clamp the x-axis to evenly spaced tick marks."""
     ax = kwargs["ax"]
 
     lims = ax.get_xlim()
     x0 = lims[0] if x0 is None else x0
     x1 = lims[1] if x1 is None else x1
 
-    ticks: list[float] = ax.get_xticks() # pyrefly: ignore
+    ticks: list[float] = ax.get_xticks()  # pyrefly: ignore
     dt = float(np.mean(np.diff(ticks))) if dt is None else float(dt)
 
     new_ticks = np.arange(dt * np.floor(x0 / dt), dt * (np.ceil(x1 / dt) + 1), dt)
diff --git a/src/jetplot/colors.py b/src/jetplot/colors.py
index 040e2ad..088d91f 100644
--- a/src/jetplot/colors.py
+++ b/src/jetplot/colors.py
@@ -3,8 +3,11 @@
 import numpy as np
 from matplotlib import cm
 from matplotlib import pyplot as plt
+from matplotlib.axes import Axes
 from matplotlib.colors import LinearSegmentedColormap, to_hex
+from matplotlib.figure import Figure
 from matplotlib.typing import ColorType
+from numpy.typing import NDArray
 
 from .chart_utils import noticks
 
@@ -16,15 +19,18 @@ class Palette(list[ColorType]):
 
     @property
     def hex(self):
+        """Return the palette colors as hexadecimal strings."""
         return Palette([to_hex(rgb) for rgb in self])
 
     @property
-    def cmap(self):
+    def cmap(self) -> LinearSegmentedColormap:
+        """Return the palette as a Matplotlib colormap."""
         return LinearSegmentedColormap.from_list("", self)
 
-    def plot(self, figsize=(5, 1)):
+    def plot(self, figsize: tuple[int, int] = (5, 1)) -> tuple[Figure, NDArray[Axes]]:
+        """Visualize the colors in the palette."""
         fig, axs = plt.subplots(1, len(self), figsize=figsize)
-        for c, ax in zip(self, axs, strict=True): # pyrefly: ignore
+        for c, ax in zip(self, axs, strict=True):  # pyrefly: ignore
             ax.set_facecolor(c)
             ax.set_aspect("equal")
             noticks(ax=ax)
@@ -54,7 +60,13 @@ def cubehelix(
     return Palette(colors)
 
 
-def cmap_colors(cmap: str, n: int, vmin: float = 0.0, vmax: float = 1.0):
+def cmap_colors(
+    cmap: str,
+    n: int,
+    vmin: float = 0.0,
+    vmax: float = 1.0,
+) -> Palette:
+    """Extract ``n`` colors from a Matplotlib colormap."""
     return Palette(getattr(cm, cmap)(np.linspace(vmin, vmax, n)))
 
 
@@ -371,6 +383,8 @@ def cmap_colors(cmap: str, n: int, vmin: float = 0.0, vmax: float = 1.0):
 
 
 def rainbow(k: int) -> Palette:
+    """Return a palette of distinct colors from several base palettes."""
+
     _colors = (
         blue,
         orange,
diff --git a/src/jetplot/images.py b/src/jetplot/images.py
index c464786..afb71a7 100644
--- a/src/jetplot/images.py
+++ b/src/jetplot/images.py
@@ -1,5 +1,6 @@
 """Image visualization tools."""
 
+from collections.abc import Callable
 from functools import partial
 
 import numpy as np
@@ -79,7 +80,15 @@ def img(
 
 
 @plotwrapper
-def fsurface(func, xrng=None, yrng=None, n=100, nargs=2, **kwargs):
+def fsurface(
+    func: Callable[..., np.ndarray],
+    xrng: tuple[float, float] | None = None,
+    yrng: tuple[float, float] | None = None,
+    n: int = 100,
+    nargs: int = 2,
+    **kwargs,
+) -> None:
+    """Plot a 2‑D function as a filled surface."""
     xrng = (-1, 1) if xrng is None else xrng
     yrng = xrng if yrng is None else yrng
 
@@ -127,7 +136,7 @@ def cmat(
 
     xs, ys = np.meshgrid(np.arange(num_cols), np.arange(num_rows), indexing="xy")
 
-    for x, y, value in zip(xs.flat, ys.flat, arr.flat, strict=True): # pyrefly: ignore
+    for x, y, value in zip(xs.flat, ys.flat, arr.flat, strict=True):  # pyrefly: ignore
         color = dark_color if (value <= theta) else light_color
         annot = f"{{:{fmt}}}".format(value)
         ax.text(x, y, annot, ha="center", va="center", color=color, fontsize=fontsize)
diff --git a/src/jetplot/plots.py b/src/jetplot/plots.py
index e57f18b..6b17e77 100644
--- a/src/jetplot/plots.py
+++ b/src/jetplot/plots.py
@@ -4,6 +4,9 @@
 from matplotlib.patches import Ellipse
 from matplotlib.transforms import Affine2D
 from matplotlib.typing import ColorType
+from matplotlib.figure import Figure
+from matplotlib.axes import Axes
+from collections.abc import Sequence
 from numpy.typing import NDArray
 from scipy.stats import gaussian_kde
 from sklearn.covariance import EmpiricalCovariance, MinCovDet
@@ -35,7 +38,8 @@ def violinplot(
     showmeans=False,
     showquartiles=True,
     **kwargs,
-):
+) -> Axes:
+    """Violin plot with customizable elements."""
     _ = kwargs.pop("fig")
     ax = kwargs.pop("ax")
 
@@ -86,6 +90,8 @@ def violinplot(
             zorder=20,
         )
 
+    return ax
+
 
 @plotwrapper
 def hist(*args, **kwargs):
@@ -249,11 +255,17 @@ def bar(
 
 
 @plotwrapper
-def lines(x, lines=None, cmap="viridis", **kwargs):
+def lines(
+    x: NDArray[np.floating] | NDArray[np.integer],
+    lines: list[NDArray[np.floating]] | None = None,
+    cmap: str = "viridis",
+    **kwargs,
+) -> Axes:
+    """Plot multiple lines using a color map."""
     ax = kwargs["ax"]
 
     if lines is None:
-        lines = list(x)
+        lines = list(x)  # pyrefly: ignore
         x = np.arange(len(lines[0]))
 
     else:
@@ -263,6 +275,8 @@ def lines(x, lines=None, cmap="viridis", **kwargs):
     for line, color in zip(lines, colors, strict=False):
         ax.plot(x, line, color=color)
 
+    return ax
+
 
 @plotwrapper
 def waterfall(x, ys, dy=1.0, pad=0.1, color="#444444", ec="#cccccc", ew=2.0, **kwargs):
@@ -281,7 +295,15 @@ def waterfall(x, ys, dy=1.0, pad=0.1, color="#444444", ec="#cccccc", ew=2.0, **k
 
 
 @figwrapper
-def ridgeline(t, xs, colors, edgecolor="#ffffff", ymax=0.6, **kwargs):
+def ridgeline(
+    t: NDArray[np.floating],
+    xs: Sequence[NDArray[np.floating]],
+    colors: Sequence[ColorType],
+    edgecolor: ColorType = "#ffffff",
+    ymax: float = 0.6,
+    **kwargs,
+) -> tuple[Figure, list[Axes]]:
+    """Stacked density plots reminiscent of a ridgeline plot."""
     fig = kwargs["fig"]
     axs = []
 
diff --git a/src/jetplot/style.py b/src/jetplot/style.py
index 4cd5eba..930535a 100644
--- a/src/jetplot/style.py
+++ b/src/jetplot/style.py
@@ -140,7 +140,7 @@ def set_defaults(
 
 def available_fonts() -> list[str]:
     """Returns a list of available fonts."""
-    return sorted(set([f.name for f in fm.fontManager.ttflist])) # pyrefly: ignore
+    return sorted(set([f.name for f in fm.fontManager.ttflist]))  # pyrefly: ignore
 
 
 def install_fonts(filepath: str):
@@ -150,7 +150,7 @@ def install_fonts(filepath: str):
     font_files = fm.findSystemFonts(fontpaths=[filepath])
 
     for font_file in font_files:
-        fm.fontManager.addfont(font_file) # pyrefly: ignore
+        fm.fontManager.addfont(font_file)  # pyrefly: ignore
 
     new_fonts = set(available_fonts()) - original_fonts
     if new_fonts:
diff --git a/src/jetplot/timepiece.py b/src/jetplot/timepiece.py
index dd86946..210d536 100644
--- a/src/jetplot/timepiece.py
+++ b/src/jetplot/timepiece.py
@@ -9,28 +9,30 @@
 
 
 class Stopwatch:
-    def __init__(self, name=""):
+    """Simple timer utility for measuring code execution time."""
+
+    def __init__(self, name: str = "") -> None:
         self.name = name
         self.start = time.perf_counter()
         self.absolute_start = time.perf_counter()
 
-    def __str__(self):
+    def __str__(self) -> str:
         return "\u231a  Stopwatch for: " + self.name
 
     @property
-    def elapsed(self):
+    def elapsed(self) -> float:
         current = time.perf_counter()
         elapsed = current - self.start
         self.start = time.perf_counter()
         return elapsed
 
-    def checkpoint(self, name=""):
+    def checkpoint(self, name: str = "") -> None:
         print(f"{self.name} {name} took {hrtime(self.elapsed)}".strip())
 
-    def __enter__(self):
+    def __enter__(self) -> "Stopwatch":
         return self
 
-    def __exit__(self, *_):
+    def __exit__(self, *_: object) -> None:
         total = hrtime(time.perf_counter() - self.absolute_start)
         print(f"{self.name} Finished! \u2714\nTotal elapsed time: {total}")