D'arce, Anaconda and North South chokes

Tonight I learnt a few new chokes, but I think the thing I need to work on the most at the moment is my posture. When we start wrestling, I've been told that my weight and head is too far forward and this results in me being easy to guillotine or be controlled from the back. Same with being in guard, posture is integral to ensuring that I can at least prepare to pass.

Today someone taught me the D'arce Choke, a variation to a head arm choke.
Submissions 101 D'arce Choke breakdown and concept.

Instead of starting on top, I was taught the choke from side control, if they're trying to hip escape away from you (facing you), you dig your arm closest to their leg under their top arm, under the arm pit and around their neck. Then with that same arm, loop it back and grab your other bicep to close the choke and tighten (like a rear naked choke).

I was also taught the Anaconda choke (another variation of the head arm choke) but I must admit, I'm a bit hazy on the details. It seems very similar, to the D'arce, except the arm is dug deep from the other end (so dig in from the neck), bring it under his opposite armpit from the side of the neck you dug and close it like a rear naked choke again.

With each of these chokes, getting that arm as deep as possible seems to be one of the key, or you can't close the choke off. 

Someone also taught me the basic North South Choke. From front control, slip your arm under the neck, push their head to the side and get their neck in between your lat and bicep. Then, with the other hand gripping the choking arm, pull it tight and sink your body down, pushing your chest forward. The sink is really important. Another submissions 101 video explaining how to execute it! Whether their arm gets caught in it or not isn't really important, as long as you have unhindered access to their neck.

Figure 4 lock (Americana) from mount. I need to focus more on putting all my weight into getting that arm down and working for it.
If the person is tightly keeping their arms to their body, I can always attack the neck to get them to open up.  Got caught with this several times.

So some points for improvement:

• Work on keeping posture upright! This is especially key when in a guard, mounted or even at the start of wrestling.
• Use my weight to try and manipulate people, not my strength. 
• Keep my weight as low and centred as possible. Extending beyond my weight results in easy sweeps.
• Attack the neck if an opportunity is not presenting itself from mount.
• Look for under the arm or under the neck choke opportunities.

Throat hurts...someone choked me pretty hard, hopefully it doesn't bruise.