Marcelo describes important steps for finishing the Guillotine: Properly executing the Guillotine-Choke involves coordination between your upper-body and lower-body; after your arms have connected together, your legs must help stabilize the position and prevent your opponent from finding an escape route. The exact orientation and configuration of your legs isn't always a certainty; find whatever way you can to entangle your opponent's legs, e.g. pulling Half-Guard, Reverse Butterfly-Half, et al. As long as your opponent cannot easily defend by passing around into Side-Control, you can buy yourself enough time for the strangle to take effect. If your opponent attempts to bail out of the hold by giving up top position, be prepared to bridge hard and take the mount position.