Do you use a primer before you apply? Ive heard wonderful things about Smashbox's primers (there is at least 3 - sensitive, normal, and another...) Primers help the foundation glide over the pores, rather than sinking into them. There are products you can get to reduce your large pores, but not eliminate them completely (large pores are apparently genetic) - though apparently Clinique (if i remember correctly?) has one that works wonders.
Personally when the skin on either side of my nose gets dry the pores there look bigger, so maybe a good - but not thick, greasy or heavy - moisturiser could help (ones for anti-shine tend to be light, and thus wont clog pores i.e. Biore Shine Control Moisturiser - very light, plus smells yummy and fresh!) Also to help your skin regain moisture, leaving a bowl/cup of water in your bedroom may benefit you as it could be a lack of humidity issue (the air in your room may be too dry).
