The main thing I think, is playing with the free foot (the foot on the outside) and seeing how and when to control their neck/head. Pushing off their neck with the free foot can get the angle pretty damn quickly and you can use it to slow them rolling or posturing by putting it either on top or below their head.
If they roll and you land in side mount, you can just sit across to the other side and it puts them back in omoplata, if they roll, then roll with them and if the roll again roll and catch their head half way through and get them in a kind of crucifix omoplata where they are on their arse.
I think if you threaten with a whole bunch of omoplatas then hazelet will come every so often, but I don't see it as the first one to go for.
I get it from triangles quite a bit, when they turn the right way, i can hook it quite quickly.