I mix my venison 50/50 with pork. I find it is too dry otherwise. I have never eaten a venison breakfast sausage I like until I started doing this. Other opinions vary, I am sure. I buy pork shoulder, boston butts, or picnic cut if you find them, I butcher and chunk them up small and freeze it in 5 lb bags. I mix fresh cut venison chunks with the half thawed pork, it should still be frozen when you grind, this gives you a better grind and keeps the sausage from getting sticky too fast.
I adapted this from the ingredients on AC Leggs Old Plantation brand sausage seasoning, which is also very good. I cannot make my sausage spicy for the masses here at my house so I don't use any hot pepper. This is a very nicely spiced sausage that as mentioned, suits the masses here. You can tweak any of this up or down by 25% and get what you want without fear of ruining a batch of meat, I have done it.
Per pound of meat I mix the following spices:
1 tsp iodized salt
1/2 tsp black pepper
1/2 tsp sage (more if you prefer)
1/2 tsp fennel seed (optional)
1/4 tsp marjoram
1/4 tsp savory
1 tbsp brown sugar (more of less for desired sweetness)
I prepare the spices ahead of time, then get ready and grind into a big pan suitable for spice mixing. I add my spices incrementally too and knead it all in with my hands, another good reason for the frozen chunks is you will have pork stuck to your hands when you are doing this part. I usually package and free in 1 quart bags, smashing them flat like 1" thick books to freeze them and they thaw quickly this way. Hope that helps.
Sadly most of my life has been wasted, but the rest I spent hunting, fishing, and trapping...