I'm a growing fan of deer tallow, mostly because I've put in the effort in learning its characteristics and limits. Other lubes work well too, but I was determined to use a local product.
I vary proportions to suit ambient temps and blend in olive oil. When I can get some I'll switch from olive oil to bear oil to further the quest for a local product. With olive oil and my own local temps, a 1:1 is ideal for cold weather, a 2:1 (tallow to oil) is fine for spring and fall, and 3:1 is great for "summer" as we know it. Understand that anything over 70 degrees is considered "hot" and a reason to sit in the shade. In hotter weather, I'd probably be shooting 4:1 or even straight tallow.
All my tallow blends are being applied as a thin film at the muzzle. It works fine to prelube patches, but you have to be careful about getting too much. Excess doesn't cause any shooting problems, but it sure gets all over everything!