I really hope this doesn’t sound like a stupid question. LOL. Anyways, if you’re lucid, can u control the DCs? Or even make someone you know appear infront of you and hold a conversation with them?
The reason I’m asking this is because there’s two things I really want to do when I have my first LD: Fly and talk to people I know. 
Moved from General Lucidness. 
I find the best way to control DCs is to use strong emotions. If you get really angry, the DCs will become violent. Become afraid and the DCs may turn predtaorial. But confidence is an emotion as well, and probably the best all around one to use. You really have to feel those emotions though, and the stronger they are, the more effect it will have.
Another option is to do some role playing. Say you encounter a group of DC gangsters. Their reaction will differ depending if you role play a police officer or if you role play the big boss.
What it sounds like The Cusp is talking about is controlling the DC’s by acting out thedream and having them react in ways that you want. There are many other ways to contol their behavior and actions, including giving verbal commands. LD’s seem to react very strongly to anythign you say out loud, including DC’s. Keep in mind, it’s sometimes difficult to give DC’s completely different personalities without changing them all together.
And yes, you can make someone appear. The best way is to tell yourself “the person I want is right behind me,” or around the corner, behind the door etc. Then simply go and get them. You may have to try once or twice, but I’ve found this the most reliable way of getting someone to appear. Of course, just shouting their name or calling them on the phone works too.