In the video and references thead i have a link to a guide on dms it covers bruising, angles of impact and general dm stuff that could be intergrated into the tut.
Defence stuff.
Against a straight punch dont try to smother it. That just increases the force generated.
Grabbing of the decap hand against a decap opener. If they still grab your head dont help them pull it off better to ungrab and go for an underhook or some kind of better position.
Against a single hand to hand grab attempt use of an extended pec wrist and elbow can swing you back out of the way and set you up for your counter attack.
When ducking be aware your arm is the thin that will probably get hit held elbow as opposed to extended can help protect agains elbow dms.
Also i vote the decap attack where you get elbow deep then contract your are be called a guillotine