Can I Improve my loose skin without surgery or would it have to be a tummy tuck procedure? (Photos)

I was wondering if there are less invasive procedures that could tighten my skin on my tummy (and the tops of my inner thighs) without having to go for a tummy tuck. I am open to lipo but I wasn't sure if there was another way that would actually tighten my skin? It's not my upper abdomen just lower but I do have a bit of a bump at my lower abdomen but I'm hoping that could improve with exercise. I also have wrinkled skin on my belly button. I am 26 and I have had two children (3 and 6).