I don't think that you waste your time, what else should you do while waiting for sleep ??? You got to spend this time anyway so why not on practicing?
As you probably know Its easyier to get WILDs in the morning cose you have more dreams at this time but I also try to WILD in the evening. I found out that I have more dream-initiated LD's during sleep when I practise WILD in the evening. It also happened that my mind continued practising WILD in the morning against my will and I got a LD this way. Thirtly its always better to be conscious instead of absorbed by thoughts before falling asleep since LDs have a lot to do with being aware, I hope you know what I'm trying to say.