A good ingredient to mix

Although BJJ is quickly and easily learned, i believe that guys who have good stand up skill, they will benefit more from this kind of practice than focus on ground work
The modification of this move is that your close arm should cover your face just like a boxer blocks a hook punch.
The other hand, which he palm plants against the wall is aimed at your opponents head or face and is a palm strike with weight behind it. If your opponent changes from pushing/driving you, that should be a hard enough strike to propel you whole body weight back into ballance.

https://www.youtube.com/watch?v=ZOu_OjRY0dU

If your opponent is not driving you down, but jumping over to get a rear naked, this is a response, with the addition, protect your neck with your arm.
https://www.youtube.com/watch?v=vM2zIknjFRM

I find this to be a good response if you find your self accidently taken down by a ground guy. They say never give up the back. I say protect your neck, turn and stand. Dont waste one moment. The second you are on the ground, get up, before they set their hooks.