Quote from ammo:
http://www.elitetrader.com/vb/showthread.php?s=&postid=2789091&highlight=out+of+my+ass#post2789091 great quote by lescor,trading, in a nutshell
Quote from Lescor:
I have a chart with a bunch of lines. When the price hits a line, I buy or sell, when it hits another line, I add. When it comes back and starts hitting more lines, I cover. If it hits the wrong lines I say "oh crap" and take a loss. The lines are just numbers I pull out of my ass that historically seem like decent enough levels to place a bet.
Seriously, it isn't any more complicated than that. Sometimes people way overthink things.