Pre-paint all the pieces before building the closet shelves to make touch-ups easier with fewer coats to build up at the end. Construct a square from the top and bottom (A) and two sides (B).
Ideally, building a closet from scratch is the way to go ... Hiring a professional to build custom shelving can be pricy, ...
Designing and organizing a closet might seem easy, but I see people make a lot of mistakes with drawers, shelves, vertical ...