How to "Thread the needle" in Jiu Jitsu (arm bind and choke)

Let's try to thread the needle, as in give a choke hole. First get your opponent down on the mat facing upwards and sit in the mountain position. Hold your opponent's left hand with yours around his head to block him/her. Get your right hand through your opponent's left hand (needle in the hole) and push your chest towards the ground. This will put pressure on your opponent. It will help in your attack as well as defense techniques.