Squats can be one of the most beneficial exercises in your arsenal when done correctly, and one of the most useless—and even painful—when done wrong. I spent years avoiding them, but finally committed myself to learning proper squat technique when I became sick of having little chicken legs.
Hard-soled Olympic lifting shoes with a slightly elevated heel are far more ergonomic for squatting than tennis shoes, which will make you wobbly and cause your knees to cave in. Hard-soled shoes will also let you push off your heel and midfoot better.
I would never claim you need any tools other than yourself in order to squat, but I'm a big fan of things I can put on and immediately be better.
After you've completed the squat and the bench press, you'll move into hypertrophy work. And, just like you in the upper-body workout yesterday, you won't take any set to complete failure. Leave a few reps in reserve (RIR) as directed in the table below.