Hmm, just today I woke up really early in the morning and was still very sleepy. So I decided to attempt WILDing. But as I kept thinking to myself "1 - I'm dreaming, 2 - I'm dreaming, etc." I only began feeling more awake. Constant thought keeps me from falling asleep even when I'm really sleepy.
Remembering LaBerge's "Exploring the World of Lucid Dreaming" he described the WILD method as observing hypnagogic imagery as passively as possible. So I'm thinking that thinking too actively won't help, rather I should relax and only think of hypnagogic imagery as lightly as possible and anticipate it but without too much mental stress or intense thinking.