what type of spell are you looking for? someone could have an amazing wealth spell, but you actually need a protection spell. sometimes casting a spell for the sake of it will result in the spell not working. while the energy you put into casting is important, sometimes the God and Goddess [or universe or whatever you believe] will stop the spell from working because it isn't needed.
start with a basic candle spell. get a candle of the corresponding colour to your problem [blue for health, white for protection] and light it. basically, that's it, you need to focus and charge the candle with energy, but basically you let the candle burn out. simple and effective.