Here is my abs routine that i do almost daily with my diet to get some killer abs. Normally i would do them after my workouts.
1.Hanging knee tucks 10reps to your chest 5 reps to the right 5 reps to the left (slow movements, pretend like you would be working on your biceps and make that same mind and body connection with your abs, DO just swing your legs up and down)
2.Kneeling Cable crunches 25reps
3 Broom stick twists 30reps (Seated in a 45 degree, lock your feet under a dumbbell or a bench)
You will repeat all that 4 times only 45 second break between each round