I was just going to comment that I read the same thing in your_mum's post, but he answered already, it seems ^.^

Doorways are tough, because your brain seems to want to accommodate what is really there in real life. It reminds me of a lucid I had where I tried the same technique with a closet door. I opened it once and got dirty urinals. Second time was kitchen appliances. I gave up after that

I've had two successful teleporting techniques...

1) Spinning. This was scary though, because the dream spun around for so long, I thought I lost it. I also do not recommend spinning while in flight, because when I finally came out of it, I couldn't control my flying anymore.

2) Closing my eyes and snapping my fingers. Many people can't close their eyes when dreaming though, so use at your own risk...