huh?
Where did you start out at if you've been working your abs for two years and they are "starting to look nice"?
I'm going to assume that you're doing crunches for your abs. Here's a helpful tip. When doing the crunch, drill your lower back into the ground. Lay on your back with your legs straight and you notice that your lower back is off the ground. While keeping your shoulders on the ground push you lower back onto the floor. From that, slowly raise your right leg and hold it high for three seconds while keeping your back flat on the ground. Now lower it and let your back come up off the ground and relax your abs. Now push your back into the ground again and do the same for your left side. Do each side three times and rest for 30 seconds to a minute and do another set. Work up to five sets.
For obliques. Learn how to deadlift. Now, grab a dumbell and place it on the side of your right foot, outside that is. Go down like a deadlift and grab it with the right hand, deadlift the dumbell. Now, only do it on one side, so your holding a heavy dumbell in your right hand, like it is a suitcase. This is the suitcase deadlift. Be sure not bend to the side, keep your body perfectly straight, the way it would be if you were holding something light, LIKE A SUITCASE!!. Do five reps and then change over to your left side.
If you want your abs to bulk up and be more dominant and "jacked" likea body builders. Give yourself a day or two of rest between each session and hit it five sets of five reps. If you want to tone it up, reduce the recovery time to 24 hrs and do only set a day and stay away from fatique, or "the burn". Back away from high rep crunches because they won't get you where you want to be.
Hope this helps and any questions ask.