I recommend starting out with a curb mount until you can do it reliably. It takes out the rolling backwards component and lets you focus on moving forward.
Then get some understanding of the forces involved in UniMyra’s static mount video..
Then use the top of a fence to brace your forearm while attempting the static mount. Over time you will rely less and less on the support of the fence (then later, signposts) until you can freemount.