Tiggertail is right: Veena, understandably, doesn't recommend that you learn the dismount first. But the dismount is how some people - myself included - got the shoulder mount. You have to be extremely careful: be close to the floor so you don't fall and hurt yourself as badly, be sure of your shoulder placement, be very familiar with your grip, and go slow (think of it like you're doing a forward roll off the pole). It's easy to become disoriented when hanging upside down like that. If you get up there and are uncomfortable or unsure in any way, don't do it. It's not for everyone - try it Veena's way first because even if you aren't able to actually do the mount, it will still build your strength and help you become familiar with the positioning and grip and such.
I used to try the SM and it was extremely crappy - kicking and flailing and... it just wasn't pretty. Just for the heck of it, I tried the dismount and it just clicked. I could feel ab muscles engaging that I wasn't aware of before. And now that I knew what I was shooting for, I was able to jump right up and do an awesome SM. 😀 But once again, that was only because I had been working on the mount previously and had the muscle memory and strength to pull it off. 😉