Draft & Texture
Base draft is easy: half a degree minimum, one degree typical. The rule people miss is texture. Every 0.001 in (0.025 mm) of texture depth needs one more degree of draft, on top of the base — so a heavily textured sidewall can want four or five degrees, not one. Get it wrong and the part scuffs or drags on ejection.
The offset figures matter as much as the angle: 40 mm of draw at 5° takes about 3.5 mm off each side, which on a 2 mm wall is most of the material. That is the real cost of a deep textured feature, and it is why deep textured ribs are usually a bad idea. More draft always helps ejection, but it moves material into one half of the tool and can create a mass where you did not want one.
Design guidance from manufacturer manuals, expressed as ratios to the nominal wall. Moulding outcomes depend on resin, tooling, gate location and process, so treat these as the starting point a moulder will refine. A helper, not a substitute for engineering judgment.