I can only speak for myself but I have never used CAD in designing my outdoor gear; I'm more of a cut-and-try sort. Or, I use existing patterns and make modifications to them as needed. Basically, nothing that I make is so complex that I need computer assistance to make patterns. My DIY projects have ranged in complexity from tents, packs and sleeping bags/quilts to stow bags and mittens. I'm making a short-sleeved polyester button-up shirt right now and am just using a slightly modified, off-the-shelf, Simplicity pattern for it.
May I walk in beauty.