I advise cutting the venison with about 15% of beef fat as Robert L E suggested. If you're looking for a recipe, as in things to add to it, dice up some mushrooms, garlic and parsley, toss that in with the burger and mix it up, add a 1/2 tbsp of worcestershire sauce and a 1/2 tbsp of liquid smoke. Grill the burgers on high on one side til blood spots show up on the top of the burger, then flip them over and grill another 30-45 seconds, take em off the grill and allow them to cool a bit, then serve, they'll be rare and juicy. Last thing you want to do with burgers is overcook them, especially venison burgers.