If this is one of your first (gee, I still remember my FIRST, then I remember my first Rack too)...

Being this is a first one for you, I'd use velcro wraps instead of plastic cable ties, because, the first few that I did, I'd stand back and admire - then I would see a lot of things that I should have done differently, and it's a lot easier to re-do stuff with the velcro pre-cut wraps.

AHEM nailed everything pretty much, in fact I wish I'd had that info a few years ago, I'd print it out and stick it on the office or equipment staging area of the shop.

Have fun, as racks are kinda fun to do, when you are not in a huge rush - and they are sort of an art-form too!