Plie Squat
The Plie Squat involves a variation on foot placement that helps target your leg muscles in different ways. In a plie squat, for example, you incorporate your gluteal muscles more than in traditional squats. This can be a nice variation to add to your routine if you need a new challenge. Just take care when lowering down and only go as far as your flexibility will allow. Here's how:
1. Begin in a wide stance with one leg crossed over the other.
2. To add weight you can hold dumbbells on the upper thighs, a single dumbbell in front or a barbell on the shoulders or behind the head.
3. Bend the knees and lower down into a squat, keeping knees in line with toes, abs contracted and back straight.
4. Only go down as low as you can without compromising your flexibility or your balance.
5. Push back to start without locking the knees.
6. Repeat 10-15 reps

Plank
The plank exercise ranked number 10 in the ACE study and is a great way to build endurance in both the abs and back, as well as the stabilizer muscles.
How to:
Lie face down on mat resting on the forearms, palms flat on the floor.
Push off the floor, raising up onto toes and resting on the elbows.
Keep your back flat, in a straight line from head to heels.
Tilt your pelvis and contract your abdominals to prevent your rear end from sticking up in the air or sagging in the middle.
Hold for 20 to 60 seconds, lower and repeat for 3-5 reps.

Modified version: Knees on ground
More intense: 1 leg in air (hold for 5-10 seconds)

Leg lift with knee to elbow
Leg lifts are one of the most common exercises for the glutes and other thighs and a great way to strengthen the muscles supporting this move can be done while lying down, but the standing version is good because it works both legs as well as core while building balance and stability.

Hold on to a wall/chair for balance if needed
Shift your weight to the right leg and , without tilting the torso, lift the left leg straight out the side at a 90 degree angle.
The foot should be flexed, and your hip, knee, and ankle should be in alignment and pointing in the same direction.
Lower the leg without resting on the floor and do a side crunch and repeat for 1-3 sets of 12-15 reps on each side

Tips
Don’t turn the leg up as you lift it. Instead keep the knee pointed forward. This will shorten your range of motions, but keep the work in the outer thigh and glues.
Avoid tipping to the side as you lift the leg. Use your abs to brace your body or hold onto the chair for added stability.