don't try and control things so much, it's really an invitation for you as a dm to be more creative. read about open hand power, it's about allowing someone else's force to hinder and frustrate them. It sounds to me like you are very forceful and that your players have figured out how to use it...
I haven't seen many post about creative spells:
in my last session kobolds had my wizard in a net and where pulling me off a dock into water - I stuck my hand in the water and cast shocking grasp (after a successful Concentration check) hitting all 3 of them
in the hay day of pen + paper...