Sit at a table and put your hands out in front of you (if you're doing feet don't put them on the table) and breath in a few times (eyes closed).
Open your eyes and concentrate on your hands. Breath in and out very deliberately. And concentrate on pumping the air to your hands. Slowly, your hands will lift up - if you do it right, it could take less than a minute to get to 2cm (might not seem like much - and you're right - it isn't - but you wold your hands going up 2 meters)- if you do it wrong - it might be more like 5 and then it would only go up a few mm.
Gradually move on to bigger things (please note thats objects that are not part of your body count as bigger then your body as they are harder to levitate).
