Want to squat more, and do it safer?
Use your belt! Most people use a weight belt as a fashion accessory, but it is a powerful tool to aid your lifts.
Put the belt on a little higher than you think you should. Right around your belly, over the bellybutton is usually the best spot.
Before you unrack the bar, inhale as much air as you can get into your stomach (not the chest) and force your abs and sides into the belt. This will increase intra-abdominal pressure, allowing you to transmit power more effectively.
As you squat back, hold your breath throughout the entire rep, forcing your abs into the belt the whole time. At the completion of each rep, exhale, and then reset the abs again for the next rep.
Try this and watch your squat increase.