Folding an Alpacka raft

First, recycle that nice sil bag into something else. If you're going to put your raft in your pack (recommended) the bag is not a practical shape to emulate.

When using the Dial method, flake out of the boat evenly. Make sure the deck is closed and free of folds, the seat has no air in it, etc. Start small, with overlapping folds of no more than a few inches. Make sure there are no wrinkles at all in each fold. When you get to the end, capture your progress with a knee in the middle, so nothing unravels. Fold, don't roll, the final row inward. You want to do two folds on the right (non-valve) side, then two on the left. These need to be tight. You want to be left with two identical masses with ~5 inches of raft in between. Than one final fold which will take on mass atop the other. Finally, grab that strap and yard away.

It will take a bit of practice to get ideal results every time. Also, the new boats have more material than the 2010 and older models, and things like the cargo fly will only exacerbate this tendency for the packed size to be bigger.

It also helps to suck the air out of your seats and close the valves. You can also suck the air out of your entire boat but if you use the Roman method it's not really necessary.
For the last couple of folds I use quite a lot of force.