Welcome to the Newschoolers forums! You may read the forums as a guest, however you must be a registered member to post. Register to become a member today!
CyanicenineYou have several different options but it all comes down to having a well fit boot. If your boot was hugging your heel well initially maybe you just need a new liner; Intuition, Zipfit, etc.
Otherwise short of buying new boots or liners you can get some "boot fitting foam" to shove in there from Tognar http://www.tognar.com/boot_heater_warmer_fitting_dryer_canting_dryers_ski_snowboard.html They have shapes specifically for heel lockdown.
Adding foam to your boot is really a last resort measure but if you can't afford new boots or liners it's your best bet for stopping heel lift.