To get this rolling...
My go-to setup is off of the jab or head-touch. I'm a one trick pony and that's pretty much all I've got in the setup department. Sadly.
When I shoot, I almost always drop a knee. I like the extra distance I get and I find it easier to penetrate when I do it this way.
For the finish, I always strive to dig my head against the side of my opponent's body and swing his legs out from under him so I end up in side control. I tend to come up to standing for the finish so I can keep driving by taking as many additional steps as needed. I've been trying to work my finish from the knees simply because I think it looks way cooler, but I haven't had much success.
Interestingly enough, my BJJ coach insists that I shouldn't finish my takedown that way. He tells me not to put my head to the side, but to keep it in front and to drive forward so that I end up standing over my opponent's open guard. Obviously this is to reduce the risk of getting guillotined, but I'm not very good (read: terrible) at that variation yet. And I, personally, dislike it. I do see his reasoning, though.
I have pretty much the same shot for grappling and MMA... largely because I learned how to wrestle through my MMA gym so I know it best in that context. And I'm a strong believer of dropping the knee because in a panick, I've found that trying to shoot while you're still on your feet can sometimes devolve into charging while bent at the waist with your arms outstretched. But maybe that's just 'cause I'm not a very good wrestler. =P
Highly opinionated but out of touch with the current MMA scene.
Support my FB athlete page!
Watch my 7th pro fight here
Watch my "Bare Knuckle" Boxing match here