I'm gonna weigh in here as a SOMEWHAT professional. And by professional I mean I studied skin in beauty school and worked for years doing said wraps and scrubs.
For the most part, time is your best bet with loose skin. It is what it is. Avoiding tanning will help with the appearance of aged skin (which is loose skin) in the years to come- that's just common sense.
The wraps/massages/scrubs all accomplish the same thing. They stimulate blood flow which in turn allows things to heal better/faster. And really- loose skin is sort of just skin that needs to heal. Some things heal better than others.
Remember all those skinned knees as a kid? How many scars do you have from it? How many faded away? Your skin healed OVER TIME!
These suggestions have worth. The one I think I disagree with the collagen lotions. A lotion may moisturize but it's temporary. Things that will really nourish and strengthen hair, skin, and nails are nutritious foods and lots of Water.