For me, i do a lot of at home workouts
. Abs, upper
body, and usually do all the running and cardio at school. Usually its the lower part of your stomach, so do i do a lot of sit ups with my legs straight up, my back on the floor, cross my feet, and do sit ups. Or another method is heel touches, where you would lay like a sit up, and just go side to side touching the back of your heel. Planks work well as well, as do V sits.
Wow, thats kinda long.