Well I've never had any luck with materialising new objects into a dream, though I seem to have discovered a method that works for me. I thought I would mention it as I've noticed it's a topic that gets brought up a lot and I've not really heard of this before, while I do see the same "expect it to be around a corner" or "call out for it" mentioned now and then.

1. Find a wall. If there are no walls, I see no reason why the ground won't work.
2. Put your hand inside the wall, I tend to go so a bit past my wrist is in the wall, I don't really feel the wall at all.
3. Make the motion as if to grab onto what you're after while intending to feel it, at some point, I suddenly feel the presence of the object in my hand.
4. Pull your hand back out, hopefully with the object you were after.

I've managed to summon a DC like this, something I've never been able to do with any other method I've heard of. I put my hand in the wall expecting to grab their hand, once I felt a hand holding mine, I gently guided them out of the wall.

I do apologise if this method has been mentioned before; while I don't post much, I am reading around a lot and have never seen it mentioned, I'm guesssing I'm not the first person to do this though.