It comes from doing.
Whatever you want to be inspired about, just do that if you want to find inspiration.
An artist, paint some.
A writer, write 100, 200 or 500 words.
A photographer, go out and take some shots.
Does not matter if what you make is shit in your eyes. Start there and through this you’ll find inspiration to make something better.
Next time you find yourself waiting for inspiration to strike, stop waiting and start doing.
If doing alone does not work, join a group and make stuff with them.
Just do. Don’t sit idle. Whatever it takes.