Yeah that’s pretty much how I’d describe WILD, you keep your mind aware but not awake. You basically move from being awake to being asleep without losing awareness and hopefully once you are in a dream you know it’s a dream and are therefore lucid.
It’s considered a very difficult technique, and there are some sensations you may feel whilst trying to WILD, mainly SP(Being unable to move), HI(Anything from swirling colours to images and sounds), Falling or sinking into the bed, being pulled into a dream. Not everyone feels all of these. And very rarely some people may experience hallucinations during SP that they find frightening, BTW I’ve been trying to WILD every night for about 2 Months, experiencing SP a number of times and NEVER had any frightening experiences.
As for when you should do it, most people say WILD should be used in conjunction with Wake Back To Bed. So they would say to goto sleep, set an alarm or use auto-suggestion to wake up after roughly 4-6 hours and after staying up for upto about 30 minutes, try to WILD. However the times vary for each person and the only way to figure out what’s best for you is to experiment 
As for how to do it there are a number of WILD based techniques, There is a page that contains links to a number of them under WILD Variations. Personally I just made it up as I went along, but those techniques provided a good starting point and lots of inspiration for me.
Click Here For The Link