Here is a fun partner core / stability drill. Partner Pallof Press
Dumbbell Side Bends
I forgot what an awesome accessory exercise Side Dumbbell Bends are. Did 3×20 each side with a 40kg DB yesterday and boy are my obliques sore today … What are your favorite accessory exercises?
Core Exercise Combo
Tucked L-Sit to L-sit, to the bottom portion of a manna and reverse.
Are Battling Ropes Too Easy? Try This
Need a new challange for your core? Here is a variation that makes battling ropes 10 times harder.
Band Resisted Jackknifes
Jen Comas Keck shows a nice core / abs exercise – band resisted jackknifes. If banded Jackknifes are too hard for your current level, you could lie on your back an do band pull ins like in video below.
Try this: Rope Plank Walk
I did and liked it. Really nice exercise engaging the whole core. Advanced Bodyweight Training Exercise: Rope Plank Walk: