Here is a small tip for tight fitting boot.
I know this isn't going to help every situation, but it made a huge difference for me. When it comes to boots I am pretty much a 10.5. Last year I bought a pair of Burton Shaun Whites in a size 10. Size 11 is just too big. Long story short, they were a bit tight during the break in period. They never really packed out like the "dealer guy" said they would. The shell sizes up perfect for my foot, but it was the liner that never stretched out enough. My foot would cramp after a long day of riding. I have had the boots for about 2 months, and thought I would make minor adjustments before ditching the boots. My first mod was purchasing some Super Feet insoles. The size insole I purchased was 9.5-11 obviouslsy. So when I lined up the new insole to my original it was a little large. I'm talking just a few centimeters on the out edges and tip. I figured I wouldn't trim the Super Feet right away (just in case I decided to return them). I tried out the insole in my boot, and walk around the apartment a bit. Guess what, the large insole helped to spread out the base of the liner a bit more to give me some additional room. Now the boot fits 100% better. Went out to the hill this weekend, and it was like walking on a cloud. I know this situation may not help in all cases. But it made a hell of a difference for me and I thought it might be worth sharing.