I agree with Erisian that you've hit a creative block, however I think you're wrong to consider you are "neglecting an old friend".
I think you need to turn it around and consider GIMP as simply a tool that you use to achieve an end result, not an end in itself.
To that end I'll issue you a challenge if you're up for it...
I looked at your GimpChat profile. It says that you have posted 30% of your messages in the Text Tutorials section, so I'm going to suggest you do something completely different to get you out of your comfort zone.
I sometimes take part in a photographic competition at
DPChallenge and right now the challenge to enter is "Human Portrait, Head & Shoulders" so I'm challenging you to produce an image with that subject.
I don't care how you create it- take a photo and manipulate it, paint from scratch, construct from objects, but do one (or more) things that fit the challenge title.
Kevin