This is really good and I'm glad you posted it and I will be trying a lot of what you mention. Also, I'm glad Google helpfully informed me that there are two different uses of "jhana", because I only knew the other one and was about to post that if you reached dhyana your first time meditating I was pretty sure you were the Maitreya Buddha.

I find I have to meditate sitting up because I become very sleepy if I do it lying down. If you can avoid sleepiness, you may escape that need. I've also heard uncomfortable positions like lotus suggested because you're trying to stop all body movement, all positions become equally uncomfortable when you can't move at all in them, and it's better to have a position you know you're supposed to be uncomfortable in so you don't try to fake a shift. That having been said, I can't stay in lotus for forty minutes.

My biggest problem when meditating is that when I focus on my breath, I switch to breathing consciously, and I can't consciously get it right. I either end up gasping for breath or hyperoxygenated (which causes paraesthesias and which I confused with sort sort of mystical body energy or something for a while until I realized what was going on). Do you not have this problem?