Ahh, don't you writers love the difficult scene? The one that stops you in your tracks because you're not sure where the heck it's going? Well, here are some of my favorite ways to put that dilemma aside for the moment and still be productive.
#1. REVISE! there are always revisions to do.
#2. RESEARCH: learn more about something in your novel. details are delicious, but remember not to go overboard, know more than you tell.
#3. CHARACTER PROFILES: go online and complete any number of personality profiles for one of your characters. Do an astrology chart.
#4. AVOID: I know this sounds like the wrong advice to give, but sometimes it's helpful to write the scenes that come after your problem scene.
#5. When you've procrastinated your pants off, had too many pots of tea and snacks, then maybe you just need to force your hand and write a lot of brainstorm drivel until something worthwhile comes out of your pen.