I simply meditate on my awareness. Not awareness of external things, but internal, like watching my thoughts and emotions and generally maintaining self awareness.

How did you learn it. There's really not much to learn. Meditation is easy to understand but very difficult to master. It takes years for most people to meditate easily, effectively and in longer sessions. As for mistakes, I can't think of many, just the usual, which is getting distracted. It's easy to get distracted by random thoughts and forget what you're supposed to be doing.

How long and how often do you meditate?
Personally I meditate at least 45 minutes per day. In sessions of 10/15/20 minutes, depends how I feel on the moment.

Do you do focal meditation (focus on an either physical or abstract object/thing), or do you prefer void meditation (emptying your mind)?
I guess my method would be the latter. No thoughts, just awareness.

Do you visualize something while you're meditating?
Nope, I am pretty bad at visualizing so I don't even try.

Do you experience any kind of hallucinations?
Rarely. Auditory hallucinations, I guess. Sometimes I would start hearing what people were talking on the radio. No radio around though.

In what position do you meditate (sitting cross legged, lying, etc)?
Sometimes cross legged, sometimes just sitting on a chair.

Do you also meditate when it's noisy?
Yes. The noise is just another of the things that can distract you, like your thoughts, and don't give it attention.

Where do you meditate?
Either on my bed or on my computer chair (to listen to binaural beats and other relaxing audio).

Why do you meditate? What keeps you practicing?
Because it increases my dream recall, awareness, relaxes me physically and mentally, and many others