What works for me (recipe was given to me by my lay-midwife).
Buy some boric acid powder at the health food store, buy empty capsules, size 0 or 00, your preference, and fill four of them with the boric acid.
Use this regimen: Night one, insert one capsule in your vagina right before bed. Night two, repeat the same. Night three, skip. Night four, repeat as night one. Night five, repeat as night one. You are done.
It worked great for me - and is safe if pregnant (better than Monistat anyhow!)
The previous note about cranberry juice - that is great for BLADDER infections. Won't do a darn thing for a yeast infection.