Here is a triangle set up that I use all the time. In the video I'll show the move, then break it down, then show it one more time. Helping me out is LockFlows own Kevinlace.
Start in the guard
Control the elbows
Shift to your side
Knee on arm
Leg over the shoulder
Move arm across
Starting off in the guard.
Control the elbows by pulling outward, behind the elbows.
Drop your left leg and shift your hips out to the side. Keeping control of your opponents arms.
Now bring your left shin over and place it on your opponents arm. Pinning his arm against his side.
Once his arm is pinned, push your shin away...
Rotate your leg over the shoulder and lock up your opponents shoulder. Still maintaining control of his left arm.
Now move your opponents arm across your body and start pulling him toward you...
Grab the back of your opponents head and garb your left leg with your right hand. Place your right leg on his hip and rotate to the left...
Now you can lock up the triangle!