agreed, any larger article of latex with closed feet (or hands) is quite awkward to move around in, especially long-term since both the dressing aid and your own sweat will start pooling at the bottom so your feet start sliding around inside if you try to put any weight on them.

i'm sure there are other techniques, but after much trial and error the best strategy i've found is simply to not get things with closed feet. all my latex stockings/leggings/catsuits have foot stirrups, so there's still some material which goes around the foot to keep it pulled tight, while any liquids can harmlessly leak out. bonus technique: you can wear ankle-high socks (made from chlorinated latex, so you don't need lube) and then put the stockings or whatever on over top of it. that way you still get the same "fully enclosed" sensation without anywhere near as much slipperiness, any liquids can be drained out with significantly less effort, and if the sock gets ripped by your toenails or whatever you don't have to replace your expensive stockings entirely :)