I would recommend working the abs, in all four ranges of motion, Top to bottom ie: crunch, bottom to top ie: leg lifts, diagonal both ways ie: side/cross crunch, Rotation ie: trunk twist. you don’t have to do all this in one day, you can split it up in two half’s, and there is hundreds of ways to hit each of these. You can also work the crunch and rotation without actually crunching or rotating, its called working the invisible. For example, you can put your self in a plank position,(push up) and stabilize yourself, hold it for x amount of time, now your are working abs without crunching, lift up a foot, and now you are working rotation without rotating.