Performing an exercise on one leg at a time will inevitably increase the difficulty.
Squat
You may learn proper form for a bodyweight squat by eliminating the chair.
Pushup
If you start in a high plank posture and finish the pushup in the same way, your elbows will naturally flare out to a 45-degree angle.
Walking lunge
You may improve your stability, mobility, and balance by doing lunges that include movement rather than standing still.
Pike pushups
If you want to work on your shoulders even more, add a pushup to your pike.
Superman
The superman is a great exercise for your lower back and the rest of your posterior chain.
Plank
When you lift your legs off the ground during a plank, you throw off your balance and force your core to work harder so that your other limbs can carry your body weight.
Dead bug
Get comfortable resting on your back with your legs propped up on a flat surface and your arms at your sides.
Overhead squat
Your lower body will reap the advantages of a squat as you work on your upper body's mobility and range of motion by extending your arms above.
One-legged pushup
Again, lifting one leg will place a greater demand on your other limbs, increasing the difficulty of the task.