You’re probably familiar with the concept of tying a string around your finger to help you remember something. This spell works along this same principal: wear something that keeps you from forgetting. I like bracelets, but often find them annoying after wearing them for a while. However, this works well if I’m trying to keep my mind on something such as, for example, trying to break a bad habit. Let’s say you want to stop an unconscious habit of biting your fingernails. Dedicate a bracelet for this purpose and each time you lift your hand to do the deed, you’ll remember not to. Very simple. I like to use a bracelet that has charms or beads dangling from it. For a very specific spell, choose some beads and create a bracelet suited just for your purpose. 
Burn a candle in the center of the bracelet to charge it, and use this chant to seal the spell:

Ring around my wrist on cue,
Help me to remember true.
Bind me to the task at hand,
To my goal, I latch this band. 

When the candle burns out, begin wearing the bracelet. Charge it again anytime you feel it’s necessary.