Pork butt or shoulder is good for fat. If you are trimming a beef brisket, that could be a good source.
Always add water to make stuffing easier.
Stuff after adding salt, because it will make the meat stiff.
Let the sausages sit a day or 2 to let the spices/salt diffuse.
Milk powder or soy is expensive, but it holds moisture.
Dont use iodine salt or table salt. Use canning salt.
Spices only last a year or so, dont use old stuff.
Dunk sausages in cold water after cooking, to keep in moisture.
Make sure sausages are dry when you smoke.
Flush inside of natural casings, makes them much easier to stuff.
https://www.amazon.com/Great-Sausage-Recipes-Meat-Curing/dp/0025668609
