Same here. I start with high-level signatures and data structures. Then I implement the functions. Perhaps the git diff helps me visualize what's left to do.

Same here. I start with high-level signatures and data structures. Then I implement the functions. Perhaps the git diff helps me visualize what's left to do. On the other hand, if it is a complex algorithm, I draw diagrams representing the edges cases and I try to give them names before coding them.