For OOBEies, the first step is akin to Serenity's: meditation and self-trancing, clearing the mind and focussing on the rhythmic heartbeat. If, indeed, you do manage to seperate, be very conscious of a thread which connects you to your body. It can be any hue or thickness. This is important, since there are downright malicious souls out there who would love nothing more than causing havoc by severing your cord. Theories on what happens should that occur differ. Some say death in sleep, others say vegetative comatose, and still some aver comatose with the chance of waking should the errant soul find its way back.
As far as I can tell, I've only done this twice. First time, I went to the Lincoln Memorial, since just about everyone knows what it looks like, and is a very recognizable landmark. The other time, I merely hovered above our house, watching the 'relaxing sleep' bubble I made rise and spread over several blocks.