Use dumbbells to work your obliques. How? Russian twists! Start seated with your knees angled and your heels on the floor (like in option 2 in the image above). Extend the dumbbell in front of you and slowly twist from side to side (twist from your waist, not your neck). As you twist to one side look at that side as well. Repeat 10 times on each side, and do that for 3 sets.
To work your core even more, lift your feet up like in option 1 in the image above. This is harder so try to hold it a little longer every time you do it.
Cheers Eights & Weights!