Any tips or hacks out there?

I'm sure there are people who practice, but we didn't. Honestly, I'm not sure that practicing would have done a lot of good anyway - it's a very different situation from what your day to day is like - different clothes, you're in front of an audience, etc. Believe me, it comes naturally.

Our wedding was outside in Alabama in July but we were both inside essentially until the ceremony (well, until our different entrances, but still), so our fingers didn't have time to swell. I assume you're carrying a bouquet, which will keep your hands up a little, so that will also help with finger swelling. If you do have concerns, try going outside for a bit on a hot/humid day (15, 30, 45 minutes - however long you think your ceremony will be) and then go back in and immediately try putting your band on. You're not going to want to have something on your finger - it could get on your dress . . .

Running your hands in cold water before heading outside might help. . .I know it helps me when I'm swollen to help get my rings off.