Here's how I cut the beef up. It use nothing but eye of round. I start by using a filet knife to cut the fat cap off and remove as little meat as possible as I'm doing it. A lot of times there will be the thin film of intramuscular fat that is easier to remove after slicing, so I leave it for the time being. I fire up the slicer and go in the direction of the grain which comes out like the piece on the left. It is cut at 1/8" thick, and from there it's just a matter of slicing with the grain using a filet knife. Now, if there's any fat, or interior marbling, now is the time to slice it out. It doesn't need to be 100% fat free, you can leave tiny bits here and there, you just don't want masses of fat because it will turn the jerky rancid during the smoke or if it doesn't, it will reduce the shelf life of the beef. When I smoke, I keep it under 150 from anywhere to 3-6 hours depending on the weather. After I know the smoker is stabilized and won't spike over 150, I check it every 30 mins or so. I like my jerky to bend, not break but, see a little bit of white when you fold it over where the grain separates. There ya have it. I don't freeze my meat before slicing, to keep it cutting clean I pull the meat from behind the blade to keep it from being sloppy, then when the cut slabs of 1/8" are on the board, just slice it into strips. They don't need to be identical, but the closer they are to one another in shape and size will allow them to pretty much smoke all evenly . Anymore questions, feel free to give me a shout!