Only leg raises and plank holds.

I do them now because if I don’t do them I’ll tweak my back.

I'm old so my ab routine is to the point and done every other day.

Ab Wheel 4 x 25
Double Crunch 4 x 25
Hanging Knee Raise 4 x 25
3 pt. Plank - Regular, then transition into L/R Crucifix @ 1 min. ea.

Hope this gives you some options. Also, don't try these numbers out the gate. Like everything it takes work to get there. Start w/ 3 sets of 10 or such. Good Luck!

What works really well for me is:

EVERYDAY
4 by 20 decline crunches (the steep one not the bench decline) with a barbell behind the back; touching the floor with the bar.
(superset with)
4 by 50 standing bent over side twists with barbell behind the back
then:
4 by 15 hanging leg raises
(superset with)
4 by 50 standing side twists with barbell behind the back

I was born with abs but leaving them just to core lifts wouldn't give me the high definition I have right now.
Try it out!

Man i can recommend you my training abs:
Hanging knee raises 3 sets 20 reps
Oblique crossover crunches 3 sets 20 reps
Cable crunches 3 sets 20 reps
Hope it will be help you. Good luck!

I had found very effective try to find a way of work your abs while working other muscle groups. Like adding a little.rotation to a rope tricep extencion or rope shoulder raiser.

if you want pretty abs your going to have to work them, i was born with them so i can stay they will look alot better when you work them and it dont take long to feel them burn

Cable crunches at all angles give me the best abs...intercostals and obliques.

I never used to train abs before. I've since included them into my training program on mon, weds, fri - 10-15mins after each workout to help with overall developement

deads, squats, front squats, weighted abs, cardio

Same but deadlifts really does it for me, my abs just burn as hell.

I personally dont do ab excercises but as you have said squat deadlift bent over rows and a new movement ive been playing with is the straddle deadlift its a nice core workout