I haven't ground lamb either, but I do own the grinder attachment for my kitchenaid mixer and use it a lot. After you cube the meat, put the meat in the freezer for around 30 minutes or so to allow it to get good and cold and to firm up. Even slightly icy is ok. Just not frozen. Some say to put the grinder pieces in the fridge or freezer too, but I don't do that. The idea of things being real cold is so the meat doesn't heat up and partially cook as it goes through the grinder.
I tried stuffing casings once and it wasn't pretty. One of these days I'll work on it some more, but for now I just make bulk sausage and freeze it in convenient sized portions. I have taken some bulk sausage, shaped it into a link shape, wrapped it tightly in plastic wrap and put it into some simmering water to cook. Like a link sausage in a casing, but no casing, just the plastic wrap to keep the shape.
¿Como como? Como como como.