Three months and already in a rut? I've got the opposite problem.
I think of a new lure to make and I'm off like a rocket, forget about the ones I still haven't finished, I'll finish them later - I am very undisciplined grasshopper. I've got two glide baits, a pike topwater, two sucker swimbaits, a shark swimbait (for my 5 year old nephew) and a bass sized top-raider all in the works.
As for painting, I have an artistic side so the artist in me just isn't happy with "good enough". I also hand paint so that makes the process a lot longer.
Your idea of rotating shapes and colors is a good one. Do something that will challenge you. Just don't do it all at once like me - not recommended