Instead of telling you what you should do, I’m going I tell you what I do, since this IS what I do:
1.) I ask myself questions about what I’m trying to accomplish artistically. I treat myself kind of like a journalist, and I let the piece’s particulars (all the fun details everyone likes to get hung up on) fill themselves in as logical solutions to my questions.
2.) I get out of my comfort zone. A very famous composer once told me that if you know what you’re doing then you’re doing the wrong thing. Other people say to change your musical diet. I go a few steps further: I read different books, watch different movies / shows, eat different foods, change my daily routines, learn a new skill, challenge myself personally, etc. You can’t be the same old person and come up with new ways of thinking. If you want to be a creative, you have to get used to the idea of changing.
3.) Collaborate. I don’t write in a vacuum. I start collaborating with my performers from the very beginning. Often times performers have tons of great practical feedback. Talk to other composers for creative feedback. Don’t bother showing your work to anyone who will say “that’s nice” unless your intent is just to share it. Share with people who you think might be the most different from you aesthetically. OR, who exactly specialize in the exact thing you’re trying to do.
4.) Put up creative barriers. Choice is a burden. You are more creative when you have more limitations put on you; more for you to push up against. Give yourself absurd challenges: make everything Fibonacci related / write the piece backwards / put a rest in every 5.5 beats (you get the idea).
5.) I make sure each project I do is different than the last one. Solo piano piece? Okay, now 3 Bassoons, now Orchestra, now video game, now I write a bunch of songs on my guitar, now I do copying work, now jazz choir, now an electronic piece. I often ask myself: “what is the exact opposite of what I just did and how can I do that?” I often measure my response to that with how I’m feeling creatively. Sometimes it lines up, sometimes it doesn’t. I spend a lot of time listening to my creative voice’s needs.
I say the word “you” a lot here but I’m really just talking to myself. This is what I do, and I have to say, I don’t ever sufffer from “writer’s block”, nor do I feel like I’m in a creative rut.
Anyway, hope these ideas help you get your own creative juices movin’.