Deer store their fat in slabs on their back, not throughout the muscle like beef and pork, therefore it is very lean. Adding any flavorful fat that you can will help, along with quicker cooking methods, but to be honest, I'm not a huge fan of venison roast from the rear quarter, as I don't care for the lean texture, regardless of internal temp. When I process my venison, I almost always use the rear for grind, or occasionally steaks if someone wants them. Now the front shoulder roast/blade roast is a different story. While that roast can be tough if not cooked properly, low and slow will give you an amazingly tender and flavorful hunk of meat, good as a roast, or great for stew and such. I personally use a crockpot for the shoulder roast with great results. For some reason, I've never done one in the smoker. While we're talking venison, the backstrap or loin, or with the bone in called chops, are great on grill. Chops direct and fast, backstrap loins slower, indirect then seared. The backstrap is fantastic bacon wrapped as Casey stated, and Malcolm Reed has a great stuffed backstrap recipe. I find that a beef and herb gravy is superb as a final touch, with mashed potatoes as a side. Hope this helps.
Charlie