Well you've seen how small my dogs are so no point telling you how big their crates are, plus I gotta squeeze 3 in quite often. I go for the largest size I can carry as they do like to stretch out when they lay down.
I use fabric crates because I can't be stuffed carrying a big heavy metal one and my dogs don't wreck them. But if I had the money I'd buy a show trolley crate so I could shove everything in the crate and just wheel it around.
I don't cover, because my dogs love watching but the fabric ones do have flaps I can put them down if I want them to rest - it's the only time I'd cover the crate. And anyway I always have a towel with me I can use (we trial outside). My next project is to sew all Deska and Tully's ribbons onto one big towel and I'll use that as a cover.
But wait until you see what I'm sewing atm. Been working on it a while and my machine broke so I've purchased a new one. I am doing mini outdoor privacy screens for dogs! Don't tell anyone, don't want them pinching my idea (she says on a public forum). Kismet won't pee while we're out so I'm teaching her to pee behind the screen, and I figure I can also use the screen instead of a cover if I want to block them, so they still get a breeze in the crate and privacy as well. I'll post it when I finish. I want to start taking it to trials and comps to see if there's a market for them.