What's the best way to improve a prolapse uterus?

Can't improve it. You can't actually do anything to improve prolapse. The good news is that prolapse isn't dangerous. Treatments are for the symptoms you may have: pain, pressure, difficulty with urinating or having a bowel movement. A pessary or physical therapy may help. Surgical options range from hysterectomy to bladder procedures.
Several options. Uterine prolapse can be a very distressing problem. There is no "best" way to treat it. Some women use pessaries (devices inserted intra-vaginally) to help keep things "situated") but there are also surgical options. I would consult your ob/gyn to discuss your options and to help come up with a solution that is a good fit for you.