Have you tried Clicker Training? I have had 4 dogs AprilLove is my first one I have trained with this method. I love it! Works much quiker than voice and hand signals only. She is one week shy of six months now and she knows down, sit, stay, spin, come. rollover, shake, up and dance (on her hind legs!)
You still need patience and repetition, but man it is so worth it. They just love to please and are eager to learn! I only spend 5 minutes a day with her on commands and we are starting to use voice only.
Here is a link for you to check it out
http://www.clickertraining.com/home/?source=wn
MaryKay
AprilLoves' Mommy
