my favourite way of doing it, is too get into skydive mount and wait. generally pretty quickly they give you the underhook and you want to get the overhook and at the same time post up onto your leg, shoot your arm through under your leg and grab their shoulder. At the same time, with your other arm you scoop up their head and hold it tight (like holding a baby tight to your bossum). then as brandon says in the vid, you want to shift your weight to the other leg and bring your leg over etc.
this is my favourite way to get in because with your arms out (diagonally above their head) its extremely hard for them to control them. and they can bridge and try and throw you as much as they want but as long as your skydive mount si good then they probably wont. and once you get it smooth enough that the leg comes up the arm goes under to the shoulder and the head is scooped up, even when they know its coming its very hard to stop.
another good place to do that set up from is gangsta lean. you can bait one arm and when they try and shrimp or do anything it generally results with them getting an underhook. for teh bait you can go for the slow triangle and its a legit bait, if they dont try and get out of it, get that instead.
i also like the skydive mount because if youre good, you cn get both sides down well enough that youre prepared for either underhook coming.
and finally remember the flow sequence that follows. once youre in mono control even if the dodge all those subs and sweep you and then your gogo and then your omaplata do the omaplata sweep, get mount back and try again. (theres a sneaky armbar after the omaplata sweep that magnus calls the kamikaze armbar.)
lol ill post this but i think theres also a thread with magnus from sweden going through it in a gi. (he is the one that taught me this)