You can get ideas everywhere. Books, movies, music, everyday life, work,...You just have to learn how to see, recognize and capture the inspiration.
I read one book about ninjutsu some years ago. There were training lessons such as these:
Concentrate all your energy on your nose for one week:
What do you smell? Is it good? Is it bad (don\'t close your nose down on bad smells!)? What does it remember you? How does it make you feel?
Next week concentrate on your ears:
What do you hear? How does the voices of people sound? What noise surrounds you? What sounds stick out? How do they make you feel?
Then comes skin/body: How you stand/walk? Where is your weight when standing or going,sitting, riding a bike,...? How do other things feel (surfaces, clothes, other people\'s skin) ?
Then eyes: This is the most difficult one, cause we are so concentrated on what we see. But you have to \"destroy\" all you see in colours and shapes and then put it together again. Also look at areas you don\'t look normaly. And also its important how it makes you feel?
And at last you try to feel with all senses at once.
I didn\'t make that whole training, but I tried it one week one sense every day. Now I sometimes try one sense for some days and then change to an other one or make a pause. Never could handle to do one sense a whole week. Afterwards you really are amazed how many things you realize only when you concentrate. And all of those things influence you and for my opinion can also be a good inspiration.
Most of all you are influenced from your eyes of course. But you have to learn with other senses too, only then you can learn how to \"see\" with your eyes (thats the reason why it was the last sense they trained!).
Perhaps this sounds all funny, but it really improved my inspiration...and it sure was fun to try it out
Hmm colour theory and books on art are one thing for me. They are so f...ing boring. I would say: Just try it! Be honest to yourself with the result. And make sketches, try colours on paper and see if they work. A good way for me to improve my compositions (on canvas, street art) was to reduce colours on only red, white and black for half a year...
Perhaps this is not really for painting minis, but it helps inspiration in generel.