Looking to define my abs a bit more?

I do my crunches, I go to the gym, I jog, I do my stuff man. I lift and all that. I really want to tone my abs though. Nothing amazing, just a toned six pack. I do bicycle kicks and crunches at least 3 or 4 times a week, no more because Im told to give resting period.

Now my issue is: I have developed the the upper two sets of abs and they're defined, but I can't seem to get the lower pack going, and I can't define the line going down the middle. The part that really annoys me is that line that's meant to push inwards separating the right and left sides of your abs. Instead of denting inwards, it actually protrudes just a little. How do I fix this and what kind of ab exercises should I be doing?

to properly define a significant line down the anterior side of the abdominals, you must do high repetitions, and high sets of isolated abdominals workouts. One such work out is the "russian forward" facing reverse side-crunch; have someone hold your legs while on your knees and slowly depress your body downward towards the floor while twisting slowly and controlled. cross your arms across you chest and keep your abs and buttocks tight. it is highly important that you do this forward and backwards wuith reptitions to the sides as well as backwards.

For your lower abs, trying doing hanging leg lifts, where you hold on to a pull-up bar, straighten your legs, and swing them in front of you. Hold them there for a second, then bring them down slowly and repeat. (Look up the exercise, because my description kindof sucks)

I don't really know about the line, but many try looking into HIIT training? It's supposed to be really good for showing your abs better.

im not going to lie, ur doing everything ive done to get my abs the way i love them. i dont know if you do this but when ur doing ur crunches and doing situps try putting a 5 lb. weight on ur stomach itll help the abs get more tone. also bicycle kicks are fantastic keep on doing those! not much more i can tell you other than my suggestion, everything else seems perfect in ur schedule. hope u get ur abs the way u want them!

try getting a tan, that helps to define abs better and its less work