Side planks are really great for working your obliques and improving your balance, but if you want an even greater challenge, try adding a leg extension! Watch this video for a demonstration of how to get into this pose.
Start in a side plank, then lift your top leg and bring the foot to the inside of your opposite thigh. Reach your top arm up toward the sky. Hold this position until you feel stable. Next, reach down with your top arm to grab the toes of your top foot, stretching it up into the full pose!
If it is not accessible for you right away, that’s ok - think of it as a goal to work toward! Some great options to practice to improve your stability in a side plank are floating the top leg up off the bottom leg or bringing your top foot to the inside of your opposite thigh (as I do in the video while setting up this pose).