When you're tired of the same old squat routine, change up the exercise with a leg press machine. It works basically the same muscles as a squat -- mainly the quadriceps -- but it gives you more control over the weight. For the multitasker, it lets you get in a couple of different exercises before you abandon the machine for the shower.
Imagine a squat when you place your feet on the leg press weight plate -- shoulder-width apart with your feet fully on the plate. Although it might be tempting to put your feet high on the plate, scoot them down below the midline and closer to the base of the plate. This gives your legs a more natural angle as you push up, targeting the quadriceps in the front of your thighs more effectively.
Instead of keeping your feet straight on the plate, turn your toes slightly outward for the majority of your press workout. This helps keep your hips aligned properly and keeps the focus on your thighs. The outward angle brings a smidge of inner-thigh work to the press. To get more outer-thigh action, turn your toes slightly inward. If you start feeling pressure in your hip flexors, lower the weight amount or turn your toes back out to keep the exercise focused on your thighs.
Think below your knees to work some muscles you can't typically target in a squat: your calves. Changing your foot position switches the action from your thighs to your calves, but start by lowering the weight. Because they are smaller muscles than your thighs, your calves need less weight -- start with about one-third of what you lift with your quads, and raise the weight as necessary for a challenging workout. Slide your feet low on the plate so your heels hang off the edge but your toes are firmly planted at the plate base. Bend your knees slightly and press up with your toes, then lower the weight so that your feet flex and the heel is higher than the weight plate.
Bring your feet closer together to save your hips while still working your outer thighs. If turning your feet inward stresses your hips, try keeping your feet turned just barely outward while bringing your feet close together -- about three inches apart. This narrow stance works the abductor muscles on the outside of your thighs as well as your quadriceps.