I have some free-flowing friends I get with every once and awhile. We just relax, laugh, and praise God. That really helps stir me up.
Also, remember, get creative in other aspects of your life. If you're not an artist, try painting what you see as you read through a scripture portion. Or whatever else might work for you. I thought I was strictly musical, but as I've moved into other areas, I've expanded. The music I've been given reflects that. It's a bit time-consuming sometimes, but the release that comes from it is awesome.
You could try writing poetry as well or singing a melody line with just vocals, no words, there is just no end to what you can do to open yourself up for creative release in the Lord. Prayer works to. Sometimes I sing my prayers and they become songs. I just sit at the piano and play whatever, and pray in song.
Hope this helps give you some ideas to work with...
Blessings. -PW