01
Define the geometry
State bounds, coordinate space, clipping, density, and transformation order before styling the result.
02
Control state
Keep mutable drawing state local and make invalidation follow the smallest region or subtree that actually changed.
03
Watch the budget
Reuse objects in hot draw paths, inspect overdraw, and test on a device where missed frames are visible.
Working rule
Make the next measurement cheaper than the next argument.
Keep a minimal reproduction close to the observation. Change one variable at a time, preserve the failing path, and prefer before-and-after evidence over a broad rewrite.