Some of the oddest things can give me a good spark. Usually I have had to experience just a tad of what 'it' is first. For writing, a word or phrase will give me something to write about.
For crafting just a picture will do.
Drawing, that is just a little different. If it's something I want to see I take it from my mind and try to put it on paper.
Usually it is something that has appeared in my mind and I have a burning need to 'make it happen'.