Having trouble with twister

Hey guys : )
relativly new to juijitsu so let me be : )

so i tired the twister at bbj class the other day :) i do not no what the F*** happened in SC i hooked his left foot and crossed my feet got up on me knees and rolled foward :)

And i ended up in half guard lmao ! (Epic fail)

but anyway earlyier today i tired on this pretty crappy guy that im alot stronger than :) and i ended up in that weird twister position he just lay there i thought he could have got up and got me in half guard because something never felt right he even put his right arm around my neck so i pinned it to the ground with my head and tried that neck crank thing eddie does in his dvd and videos but let go as i thought i was doing it wrong and something happened and i ended up in the mount and taped him with an americana(which never seems to work on strong guys) : )

has this ever happened to any of you guys : )? can you tell me what im doing wrong (alot probs) and possible write some steps to get it !

i even have eddies book ! and i did what i thought was right lol!
but yeah i need to do some studying