A DILD is when you are going about a regular dream (not-lucid) then something during the dream triggers your awareness and you think "..im dreaming!" - Dream-Induced-Lucid-Dream

I assume what your trying to do with SP is WILD, not DILD, which is Wake-Induced-Lucid-Dream, where you go straight from being awake in the real world into the dream world. To achieve this your body has to fall asleep (SP) and your mind HAS to stay awake, otherwise you will just fall asleep and enter a regular dream. Seems like your on the right track though, try keep your mind awake and visualize a scene infront of you, eventually a dream will form infront of your own eyes and you can transition/step in/teleport/fall into the dream and bang, lucid.