I splitted your question into a separate topic so more people could see it.
Wake to Sleep is a method that Tracy recommends when you have ruled out other reasons for night wakings or early wakings as teething, pain, illness, development, etc. and the wakings are pretty predictable in time (that is lo waking at a given hour or an amount of time of sleep, say s/he wakes 3 hours after going down no matter the bedtime).
Sometimes after a "crisis", like an illness or a series of actions result of accidental parenting, some issues are solved but the babies/toddlers are used to wake at night without any reason and have trouble or don't know how to go back to sleep.
So, to answer your question, yes WTS is a strategy you can use to prevent early mornings if your your lo if s/he is still tired by the waking time.
What you do is go into his/her room 30-45 mins before the usual waking is (you should go in at 415/430 for example). You rub his/her back or tickle her/him softly till s/he stirrs, sort of wakes but not wide awake just a resettling. Then you go out of the room. The theory behind this is that with this waking you restart the sleep cycles hence lo will start a new sleep cycle that won't be over in the next 1.5 hours. You have to do this for 3-5 days in a row and then stop to see if s/he can make it the whole night. If it keeps going then you have to try for 2 weeks in a row.
If your lo happens to have very light sleep (as mine does) and is wide awake the minute you enter his/her room then you should do pd or wi/wo to help him/her go back to sleep.
HTH and let me know if there's anything else we could add as info.
