Lying
Under
Covers
Inside
Dream

When you think the word lucid, you should think of this. When you realize that you are just lying down imagining all of this, the fact that none of it is real and that there are no limitations should follow.

When I want a DC to disappear I just ignore it, unsummon it, or teleport away. Ignoring it should make it disappear if you take it out of your mind. Nothing can survive in the dreamscape without your attention is something that I think in order to do this. I don't 100% agree with it, but it has been helpful.

Check out sivasons dream yoga class for ideas on how to ignore things better. Meditation is a great tool to LDing if you wish it to be.