Shift your right leg backward and drop to your right knee. As you drop to your knee, twist your body leftward to throw the attacker. Here is one of my favorite striking combinations and choking techniques for the street. From a on-guard position facing your opponent. If you do not know Osoto Gari you can pick it up on any basic Judo video.
Attacker begins with a left jab towards the defenders face.
I use Kake Uke - hooking block. Attacker follow with a right hook to the head. Defender steps slightly forward with a rising elbow strike in to the soft tissue of the under side of attackers right bicep. Now the defender needs to break the attackers balance and put him down. You can find this before you begin practice by running your fingers up along both sides of the windpipe.