Tonight, we reviewed two of the basic submissions from the guard: the Triangle choke and the Arm Bar. We started with the triangle, since one attack flows naturally into the other. So let's start with the general scenario. Please keep in mind that these are my own notes to remind myself of what I learned and should not be mistaken for an instructional guide.
The opponent is posturing up, with one hand on your chest, gripping your gi. First priority is to break his grip on the gi and to control the opponent's wrist. Grab the opponent's sleeve with the opposite side hand (eg. if he's gripping your gi with his right hand, you grab his sleeve with your right hand). Grab your right wrist with your left hand and pull up and across your body, so that his hand ends up off your body and ideally over your right shoulder or center of your chest.
Adjust your grip so that your left hand is controlling his right wrist. Straight-arm his wrist right into his chest. It should be fairly difficult for him to resist this. If he tries to pull his arm away, then he unknowingly helps the process. Grab his lapel with your right hand and pull your opponent down towards you. Maintain the straight-arm on the right wrist. As you pull him down, open the guard and hop your left leg over his right shoulder. Re-establish control by hooking your legs together. At this point, you should be in a triangle set-up position, but you still need to create the proper angle.
Before making any adjustments, reach up and grab your left shin with your right hand. This should allow you to keep your opponent trapped as you open your guard to adjust the angle. Don't let his left arm find it's way out. Use your right foot to push off either your opponent's left knee or hip. This will allow you to affect his balance, as well as adjust your angle. If you've done the push-off properly, then your left leg should be tight against his neck and you can loop your right leg over your shin to complete a figure-4 sort of position. In order to complete the choke, you need to get the remaining arm (the left, in this case) across his body. To do this, you need to lift your hips off the mat. His arm will naturally pop up as you do this. Find his elbow and then push it across from your right side to your left side as you drop your hips. Pull down on the head, if necessary.
In the event that he defends the triangle attempt, you can switch to the arm bar easily enough. Clamp your knees tightly against the opponent to try and limit his mobility. Control the arm that you still have trapped (the left, based on the set-up above). Extend your left leg, maintaining the hooks you established while going for the triangle. Try to keep your hips on the ground. This will give you a bit of distance, as well as attack the opponent's balance, moving him to your right (his left). Control the trapped arm. Control the trapped arm. Control the trapped arm. I can't stress that enough. The opponent's elbow should be ripe for the picking. Push off his left knee or hip again, if necessary, while biting down with your left leg. From there, swing your right leg over his head and squeeze tightly with both knees. You can push his head to the side to make it easier, as well. From here, it's just a matter of raising the hips and hyper-extending the elbow.