I've never really tried FILD before but it looks like a promising technique. I should give it a try.

The approach I would take in learning how to FILD is to first figure out how to fall asleep before learning how to fall asleep in the same way, only while doing the technique.

How many times do you attempt FILD each night? The more times you attempt it each night, the more likely you are to succeed.

If you have trouble falling back asleep, don't get up from bed upon awakening. Doing so will make it harder to fall back asleep. Only do WBTB if you have trouble maintaining enough focus long enough to succeed.