a cheaper way than useing a trimmer is to use a razor to cut off long hair. i take my razor, pull the hair taut, and then smash them together in a way that i can't quite describe, but perfectly trims the hair. i've never cut my fingers or yoni area with this technique.
this may sound really weird, but i also have tweezed the outer bikini area since i was about 12. i don't get ingrown hairs this way, like with razors, and it keeps me smooth for longer.
just my 2 cents!