The first thing to look for is to isolate your opponents nearside arm. Your opponent will do their best to keep this arm tight to hide it. Capturing that nearside arm allows for great control as you can flatten them onto their back when they try to turn into you.
Once you have control of the nearside arm, switch your hips to the scarf hold position and pass your top leg over your opponent’s head. Lean back to straighten your opponents arm, finishing the Nearside Armbar.