Banana Turnover is sort of the "gateway" to Horizontal/Excalibur/Vertax play. Not only does it help tremendously in landing into an initial mount after throwing for all level of players, but, for a beginner in the style, it's a quick in-and-out trick that you can land just to practice your horizontal throwing.
When first learning horizontal moves, you may find it helpful to lean back a bit and throw kinda more upward than you think you need to. I mean, it's all a matter of practice to throw at the proper angle and maintain that angle, but those two things did help me when learning. However, you might want to assume a more normal posture (stop leaning back) once you get more comfortable with the style, because it does look a little silly to spectators.
Contrary to popular belief, maintaining the angle of your yoyo is NOT about speed. It's about forceful, accurate, purposeful movements. Make a conscious effort to swinging the yoyo in the same plane it's spinning. It also helps to use a yoyo with a large gap and huge open catch area, just so any sloppiness you have in the process of learning doesn't hinder you as much.
Oh, and by the way, you can bind the yoyo back from horizontal however you like, but you've gotta be smooth with it and not pause. That's why I use the Suicide Bind, because I find it easy to fluidly swing the yoyo into the mount and then continue that swing straight into the bind. ...Plus, it just looks cool.