I know I'm late to the party, but boots shouldn't be snug when you're trying them on in the store. When riding, your feet are going to swell. Boots will be more restrictive and hotter than "shoes," so you want to have a larger boot than you would shoe, and you want it probably a half-size larger than you think while trying them on in the store. One of the best things I ever did for my feet was start wearing slightly larger shoes/boots. I always wanted them a little snug, thinking that meant support. It doesn't. So, now I remove the "stock" insole and buy a proper orthotic with a slightly larger shoe/boot. Much more comfortable throughout the day/ride.
boots break in tho... or you not talking mx boots? im confused.
even with leather riding boots, they'll stretch a bit. the ones i have are now are like a noodle. Ive always bought (any) boots to size that they might be a little tight/snug at first, knowing they'll break in.
wearing a good sock, your feet will be alot more comfy.