I had those endless and unsuccessful WILD attempts too... but they are not completely worthless, because you learnt about how your body starts to feel, and you will be less surprised when the real WILD occurs !
I would suggest to experiment with the hour at which you do WILD. When I started, I did it sometime in the middle of the night, but I was not sleepy enough, so concentrating on WILD kept me awake and I couldn't enter the dream. I discovered that it was much easier and faster later, near the morning.
You'll have to try different times of the night and see which one is best for you (If you oversleep after the time you're supposed to get up for work/school, for example, then this might be the good time). Also, vary the amount of time you wait between wake-up and WILD; tutorials may say 30 minutes, it may be shorter for you.
Good luck !