What are critical DFM guidelines for injection molded plastic parts?

Injection molding DFM guidelines include: maintaining uniform wall thickness (recommended 1.5-4mm) to prevent sink marks and warpage, adding draft angles (0.5-2 degrees per side) for ejection, using radii at all corners to aid flow and reduce stress, designing ribs at 50-60% of wall thickness to prevent sink marks, placing gates in non-cosmetic areas, avoiding undercuts or designing for side actions, and considering material shrinkage in mold design. Weld lines should be located in non-critical areas.