[ggm]

Screenprinting multiple colours, and like additive, point registered techniques. Higher points for things you have to do in some sense "backwards"

Knitting, writing knitting patterns. Both iterative and recursive qualities inherent in knitting complex clothes (mathematicians might call them a manifold)

Most games of patience. Many games like "nine man morris" or "solitare" puzzles, Rubik's cube (group theory)

Rowing, cycling. Cyclical repeated path following.

Train, carriage, aircraft and bird spotting. Sets, set theory, groups, sequences. Yes, obsessive behaviour too..

Cooking. Generating complex recipes