Our feet are one of the most individual parts of our bodies, and since we're all a little different anyway, you'll have to discover what works best for you. Unfortunately this usually means a lot of $$$ spent on footwear that you end up not being able to use, since it's pretty hard to figure out how a shoe is going to work on the trail by hiking around on your living room carpet!

A lot also depends on the weight of the pack you carry and on any extra body weight you haul around (I'm unfortunately something of an expert on the latter).

I haven't found my feet swelling, but I do find that they tend to spread. This has been a cumulative effect over the years, aided by past pregnancies (which is like carrying a 30 lb. pack in the wrong place!). Long, long ago, in a galaxy far, far away, I wore a size 7.5 shoe. Now it's size 9.5 in some shoes, 10 in others!