Grape-Vine/Saturday Night Ride
A wrestler knows the technique of wrapping your legs around the person trapped in mount's legs as a Saturday Night Ride, most grapplers or other sports identify it as a Grape-Vine. When this movement is locked on you and you're trapped underneath, it becomes difficult to bridge your hips to roll somebody, and by their holding down your hands it could become difficult to move at all. Here are some following suggestions I typically use when not battling in the cage (because you're just asking to get your ass kicked if you leave your face open in the cage while mounted):
Your arms: Your arms are trapped by the wrists, knuckles-down on the floor not far from your head. Arch your back and pivot in one direction, straightening your arm as high as possible above your head, still trapped on the floor, though. The direction you are pivoting is the focal point- if you pivot right, that's the direciton to escape...for the sake of this technique, we'll turn right. Pivot all the way onto your right shoulder, lifting your left shoulder into the air. This is doable only if you straightened your left arm all the way above your head. Curl your left arm as you pivot, allowing the bend of the arm to rest on the top of your head. Use your left arm to clutch your opponent's arm that is trapping your right. Bring your elbow over your head and into your chest, trapping the bend of your opponent's arm (the one that's holding your left arm if it is still), and curl your right arm into your chest as well. Your arms are essentially free- don't let them get caught again.
Legs- While locked in the grapevine, you're going to utilize a combination of my instructor's movement, the pooper-scooper, as well as my own. Straighten your left leg to the best of your ability while still caught in the grapevine. Use your right foot to step on your opponent's ankle (the one trapping your left leg). Lift your body with your right leg, applying as much pressure on your opponent's ankle as possible. While your body is suspended, hips out backwards (to the right) as much as possible. Free your left leg before your opponent catches on- doing this simultaneously with hipping backward makes it much easier (note hipping out is designed to create space in this technique, not to escape the mount). Drop your left leg as flat as possible on the floor, aiming your knee at the ankle area of your opponent's leg (to the left). Now we utilize the pooper-scooper. Bring your knee through the bottom of your opponent's leg. Step your right foot over your opponent's free ankle (this can all be done with the grapevine still holding your right leg, BTW) and sweep backward to trap it under your right leg. Pull with the right and knee out hard with the left, and you have made it to half-guard. Take care in escaping half-guard, which should not be hard using the snake-out method.
This ****'s kinda hard to type out without visual aids, but I hope this helped.