Adapt a brassiere by sewing up the back closure, cutting the front open and attaching Velcro strips. Sew rubber strips to the inside of your skirt or slacks waistband to keep a shirt or blouse tucked in. Fit slacks with side zippers in the legs for ease in pulling them on and off. Zippers in the inside seam to the knee may accommodate a cast or brace. Buttons require the most movement and coordination, snaps or dome fasteners are easier.
Zippers are faster and easier still, and simplest of all are Velcro strips.
Outerwear Try designs that are warm, water proof, and can be layered for change able weather. Since you want to be able to move freely, look for designs that have deep armholes and loose shoulders. A hooded poncho or cape is particularly suitable for protecting a wheelchair user from rain and cold. These can be purchased at camping supply stores. If you design your own, cut it just below waist level at the back and allow enough front length to drape over the knees.