Get it out of your head. Don't rely on internal monologues or visualizations. Do the actual spell, speaking out loud and doing physical motions with physical objects of some kind. This will help you make sure you're not just thinking about something and then expecting results from it. Even if you're just lighting a candle or writing names on a bay leaf to put in your shoe, when you do those things you are 100% certain you actually did the spell. Coming up with an actual sigil or spell will also make sure you have some clear idea of what you're trying to do. If it's all in your head, you're probably just imagining or "willing" things, and then you can expect sketchy results. The same goes for anything with spirits, gods, demons: if it isn't something you are doing an actual ritual, spell, or something real to contact, assume whatever happens is just your imagination. If your methods are junk, expect your results to be junk too. Especially when it's important, give it the kind of attention and work something important deserves.