WBTB is to take advantage of a certain stage of sleep, right? since everyone's different, that stage is probably not exactly at 5 hours after i fall asleep. i know i'm supposed to "experiment" and figure out exactly what time i should wake up, but i don;t know how.

?s:
-what is that stage that i'm trying to get up at?
-how do i recognize when i've found the right time to wake up?
-if 5 hours is wrong, what do i do to find the right amout of time?
-do i adjust 10 minutes/30 minutes/1 hour/2 hours to do the above?
-how many tries does it usually take to get it right?