Catherine Imes, Master of Sports with the AKC has great videos to help your competition lifts technique.
She covers the usual mistakes, and how to address them so that each rep is legit.
“My advice to you if you train alone is to get a video camera and watch your sets. I do this nearly every practice because I’m certainly not above a bad rep and I like to make sure I’m not developing bad habits as I go. This is really one of the few things we can do when we train alone.” C. Imes
Click the discipline to watch the video