What are some procedures that people who need organ transplants do while they are weighing on an organ?

Depends: For people awaiting a kidney there is dialysis. For hearts there are lvads ( left ventricular assist devices) for those awaiting lungs there is oxygen and sometime ventilators.

Depends on the organ: Procedures depend upon type of organ failure: for example, kidney failure patients often need dialysis access placed (catheters or fistulas); liver failure patients may need fluid removed from abdomen, endoscopy for varices; pancreas transplant patients usually only need Insulin injections; heart patients may need an implanted assist device; lung failure patients may need oxygen and/or ventilator.