I was washing sprues based on old school advice in FSM books, stopped after reading it isn't necessary, but started again because I like to. I always open the box when I get it, usually I already looked for aftermarket stuff online. I take blue tape and make a quick label on each sprue with the letter on both sides in big sharpie letters. I hand them from nails on my workbench upper cabinets, A-Z. I put all the special and clear parts out of the way. I read the instructions and use highlighters of four colors to mark special instructions, where random decals or photo etch is called for, which option I am doing, and paint callouts. If the kits says or shows which parts are not used, I may cut those off and make a pile of them off to the side (just in case I need them).
It works for me and my OCD.