Hook and eyes seem to be best so far that I've used. Either that, or sewing/gluing pieces of velcro. (for the waist part at least)
As for the legs - I've found it easy to use the slight stretch most furs have as an advantage. making them snug enough around the knees/calfs, and they'll hold up by themselves. I also know people who have threaded leather ropes (avail at micheals/craft stores in the jewelry aisle) and used those to tighten them around the legs.