Now, jiujitsu is all about setting up a move with other moves.
The omoplata is a move that allows you an unbelievable amount of submission options.. the most common is probably omoplata to triangle to armbar. (Ala, Antonio Rodrigo Noguiera vs Enson/Coleman)
Since the sport is so widely studied, this combo is one that you may catch on someone but, there won't be too many people fooled by it.
Another alternative would be the omoplata to toe-hold. Leg/foot submissions are generally not studied for beginners and like all submissions, be very careful when applying these. The omoplata to toe hold offers you a submission while controlling the trapped arm. And this submission hurts. This is the same move Frank Mir used to beat Tank Abbot in the UFC, and the same submission that Minotauro attempted on Enson in Pride.
Step 1: Get a knee in
First of all, you can't get an omoplata if you don't have one knee within your opponents hands. Notice how Justin's right knee is in between my hands.. This means he will trap my right arm. He controls my right wrist with his hand by either grabbing the wrist or behind my tricep.
Step 2:Switch the Hips
As soon as Justin has a knee in and the arm controlled, he shifts his hips out to the left, pulls on my right arm, and kick his left leg up and over my right shoulder. This produces the needed leverage to force me forward and for him to get himself back in a sitting position. To produce momentum, Justin has posted on his right leg while he turns. Notice how he still maintains control of the trapped arm. It is very important to make sure that you grab your opponent's belt/torso as you complete this portion to prevent them from rolling over.
Step 3: Complete the Omoplata
Justin triangles his legs around the trapped arm, bases upward, and secures control of my torso. At this point (the omoplata) justin can go to many submissions (i.e. he could swing back in for a triangle, he could push his hips forward for a shoulder lock, he could try a kimura etc.. this is a highly dominant position. Justin however, will go for his favorite move. The toe hold.
Step 4:Get yourself a foot.
You have to attack the same toe on the same side. That is, if you trap the right arm, you get his right foot. As justin leans back and turns in to my body, he extends his hips outward so that he can flatten my posture. Since I am now on my stomach, it will be much more difficult for me to roll out. Justin grabs my foot with his left arm and wraps his right arm around the leg.. much like you were going for a kimura.
Step 5: The grip
IDEALLY, you want the left hand gripping the foot on the outside, where the pinky toe is...Justin's grips is a little off. You want the cup of the hand to be on the blade of the foot... Its pretty solid from here though. To add more strength and leverage, it would be much more effective to get your right hand higher up on your left forearm. The higher up, the more leverage, thus, the easier it is for you to apply. At this point Justin's right arm is gripping my forearm in a four-finger grip but it is way too low and has little control over my foot.
Step 6: Apply the toe-hold
Justin readjusts the grip by moving his right arm higher up my left foream. At the point he has the hold, he turns away from me while turning the hold towards him and upwards.. it's good to keep the trapped foot as close to your body as possible to make it very tight. (you can do this by pulling in with your right arm while your left hand pushes the foot up and away.)
DURING THE ENTIRE PROCEDURE, MY RIGHT ARM IS STILL TRAPPED IN THE OMOPLATA, PREVENTING ME FROM ROLLING AWAY OR ROLLING WITH THE TOE HOLD.
So that's basically what the combo is. try it out, it adds nice variation and is fairly simple. There are small details that need to be said so practice till you undestand it fully. Fun move.