These are my favorite dumbbell exercise for the entire body. Everybody is different, what may work for me, may not work for you. I really like these exercises and get good overall results from them.
Russian Twist With a Dumbbell
It took me a while to master this. You can do this with a kettlebell or a dumbbell. I figured out that if I sit up too high, and keep the dumbbell too close to my body, I’ll get a hipflexor exercise and more of a balancing act. I started leaning back to my tipping point and experimented with extending my arms. Somewhere in the middle, I felt my abs and my shoulder and that was the sweet spot for me. Everything worked and the burn in my six pack was sweet.
Use a pair of dumbbells that are light enough you can experiment with but not too light that you don’t feel anything. If your dumbbell set is too heavy, your just tip over before you get a chance to anything. I know this may not sound very specific, but that how life often is when you don’t have an experienced guide right by you. You have to experiment and find out what works for you.