Don't stand on your heels! You don't have to completely move over to digitigrade locomotion, but... standing flat footed for long periods of time seems like it could be painful.

Keep a bit more weight on your forefoot. Your knees will thank you (more stability now comes from your ankle, which bends left/right much more effectively) and your calves/quads will do a lot more work.

Of course, it is useful to note that if you're used to locking your knees while standing, you're gonna have a bad time. Expect some soreness.