Teaching the horse to 'park up' for mounting using the method described above (i.e. Stick over back; lovin' on the near side, pressure on the far side, release when get what you want) is a starting point.
Please be careful though when doing this on the ground that you can disengage the HQ and get them to yeild away from you first. If a horse learns to bring his butt/side in to you before he knows this then things can get dangerous. Even a horse that wants to please you could accidentally crush you into an obstacle just through misunderstanding. Horses with a lot of 'try' will often attempt every trick in their repetoire to try and please you...or at least to get the pressure off them...so a good HQ yeild first is really important.