I mix 5-10% cheap burger or sausage to venison before I freeze it up just to hold it all together when I make burgers or venison meat loaf.
I love venison burgers and venison loaf!
I also mix in 1 egg.The single biggest thing that has improved my burgers is a
Burger Press.I bought a cheapy plastic one couple yrs ago(less than $10).Its ribbed for a better release of meat after pressed.You can press a square or round burger or sausage pattys and then freeze em up.
It also prevents over working the meat when your trying to mould that perfect burger by hand,which can make a tough burger no matter how you cook it.Coat the press with some lite oil place meat in press and squeeze the hell outa of it. Peel it out into hot pan or grille with a spoon.
Use the thinnest spatchula you can lay your hands on.I bought 3 of these thin ones just for flippin burgers,eggs and pancakes.The thin ones are very flexible and prevent breakin up meat when sliding spatchula under burgers for flippin.
You can't or at least I can't flip a venison burger like you would a beef burger.It takes a little gentle finess to keep it all together.
Once you get the hang of it you'll be makin some good lookin 1 piece venison burgers
Hope that helps someone - works for me anyway