Custom liners are old news by now, but if you've never been fitted with a pair, do it.
I've got big ol' feet. They're a wide, high-volume size 12. I have problems fitting into most shoes including dress shoes, running shoes, and even sandles and such. You can imagine my problems with climbing boots and shoes (I swear that clmbing gear companies just don't make gear for normal-sized people - but thats for another review).
For years I've worn Koflach Degres with the standard liner. By the end of each and every trip, my feet hurt so bad I can hardly stand. I never got custom liners because they're so expensive. I once found some
used liners on ebay and tried to cook them myself. What a disaster. I highly recommend getting them fitted by a professional.
When I was in Colorado for Avy II at Colorado Mountain School I broke down and stopped by Neptune Mountaineering (awesome shop) in Boulder and had them fit my old shells with brand-spanking-new Intuition Liners. The sales guy took his time, fitted my feet with the new liners, cooked them up and sent me on my way.
Unbelievable. Seriously. Like heaven. Like walking on pillows. I've never had comfortable feet before. When your feet are comfortable your whole body is comfortable. You climb better, longer and, most importantly, have more fun.
Anyway... um... yeah, I'm a fan.