I tried this too, but then I started getting up while I was still mostly asleep, walking across the room to turn off the alarm, and then going back to bed again. I even tried putting the alarm in a closet, but I'd still get up and turn it off.

What worked for me was (1) going to bed at a reasonable hour and being sure I got 8 full hours of sleep, (2) giving up coffee, and (3) going running every morning (I lived next to golden gate park, totally worth it). I was able to get up early, got tons more done in the morning, and I also got in shape. Best thing I've ever done.

This sometimes happened to me when I was in uni. I'd leave my alarm (my phone usually) on my desk on the other side of the room. Some days I'd wake up and see my phone on the pillow beside me.. when this happened there was always an "OH SHIT WHAT TIME IS IT" panic since it meant that I got up, turned off the alarm and went back to sleep.

I also used my computer as an alarm clock for a little while. I wrote a program that would set the windows volume to whatever value (0 to 100) was passed as a commandline argument and then I set up the task scheduler to run it in the morning. This way, I could play music quietly at night and in the morning the volume got cranked up to 100% to wake me. Worked well until one morning there must have been a power outage and my computer was off...

Solving puzzles to turn off an alarm doesn't work for me either - my still asleep self is quite clever at pulling plugs, taking out batteries or simply just smashing a persistent alarm.

Luckily, unless I'm really tired (eg go to bed at 6am, get up at 8am), I normally wake up before I need to get up. Actually getting up is a lot harder than waking up tough.

Clearly getting out of bed isn't all the work in waking up, but it's a good start. If done in addition to the other things you mention, it's helpful. Getting up just seems to get your juices flowing better, at least based on anecdotal evidence.