You can read about DEILD here. Probably more people would know about it if it had it’s own acronym, you know, the thing with the mouse-over-text and info pops up. Anyway, DEILD is a quite reliable and easy way to enter dreams if you manage to wake up and not make any movement or open your eyes. Of course, you can even make up a mantra for this if you plan to use it as your primary method.
As for the journal, it helps your DR. Whereas a bad DR may mean waking up in the morning and not remembring you even had a LD last night.