I know how hard this game can get, so here is a few tips for you
1. always pack a bunch of buff spells: charms or wards to help your spells in combat.
2. pack many healing spells: try to at least have your pixie (or fairy) to keep you with at least a minimum amount of health.
3. pack some weak spells: have you ever fought a tough enemy and he is down to the count, and you are waiting for a rank 5 or 6 spell to come around, try to pack rank 1 or 2 spells to take them down fast. Helped me many times