Hi there I think that you maybe overcomplicating things a bit. I know all about this, believe me... If you take the same approach as transcendental meditation you should be fine. But that means taking a passive approach and not expect anything. I usually lie perfectly still in my bed and just meditate on nothing - expecting nothing. I quickly go into SP, and the stillness of the mind seems much easier to achieve. (If you at this point begin to wonder which technique to use next, you'll blow it) Just lay perfectly still with a silent mind (takes practise) if hypnagogic imagery happens you should just ignore it, just lay still and don't think - after a while you may go into a dream without any active action from you - OR you may fall asleep. If that happens you have a good chance of waking up shortly after either with the ringing in your ears or with a false awakening. So always make a reality check whenever you wake up. Make it a habit.

If you get the buzzing sound in your head - you should just will yourself to get up of bed. Its almost a physical act, but not quite. I always get up this way - and have succeded everytime I have gotten to this state. Then I find myself in my bedroom and can venture out from here.

Good luck - and remember to "expect nothing - and think nothing" during your attempts, it all feels very natural when you get far enough - just wait for it.
Sometimes you will be too tired - other times you won't get anything out of it, but the transcendental meditaton in itself will be good for you. (Maybe even giving you easier acces to paranormal stuff - giving you easier acces to LD's and so forth - If you ask me at least.)