Whenever I draw somethin I try not to think too much, cause it hurts when I think too much. Use your imagination but don't pressure it, let it wonder freely, feel relax and let go of all anxiety, worries or uncertainties. There are times I just let my hands draw as it please, like it has a mind of it's own. Drawing is fun, not a burden. Cause when you think too much when you draw then your head will explode and your brain splatter all over the drawing table. Or you could end up with a brain tumor. Just an advice.