There's a rule of improv that I think I've mentioned before. There's really only one rule of improv, and it is to always say Yes, and...
I've been listening to a lot of the Writing Excuses podcast lately, and they often apply this rule to writing. With some slight expansion, this Yes But No And rule can really help when you're working on a scene and just can't figure out what comes next. Whether you're chugging along and the scene hits a dead end our your working on plotting and need to figure out what comes next, the Yes But No And Rule can help.
Let's do a couple examples. You're working on a scene: It's the middle of the night in the holding tent for circus elephants. A woman in a wedding dress runs in, looking for the map that is going to lead her to where her fiance, the Night Cartographer, has been taken. Then you get stuck. Think of the Yes/But. She finds the map (Yes), BUT the key is missing. Now you know what step she needs to take next me.
Another example. You're scene is two teenage boys at a chess tournament, and one boy has discovered that he can move the chess pieces with his mind. He gets kicked out of the tournament for cheating (No), AND the queen starts following him wherever he goes. Now you have the next conflict he has to deal with.
Basically this rule amounts to adding complication. Take whats happening and make it worse. If your character finds what they're looking for, give them something else they have to find. If something bad happens, something else bad happens too.
How would this work for the scene your working on now?