I've taken a break from learning how to dreamwalk for a while, so I can get more control over my dreams themselves.
At first, I could only influence things that were already in my dreams and not actually create anything. So this morning, I gave it a go.
I fell into a usual lucid dream, aware that I was in my bed but not able to see anything. After I imagined that I left my body, my room started to materialize. (I still need to figure out how to change the environment right from the start...)
Anyway, I walked over to a spot on my bedroom floor, and tried to see if I could make a flower. I pretended to plant a seed in my carpet, and held my hand over it for a while. Suddenly, a whole bouquet of red roses shot up from the floor. They were slightly limp, and I hadn't wanted them to grow that large, but I was happy that I at least made something.
After that, I decided that I wanted to trim their stems a bit. I didn't have a pair of scissors around, so I tried making one by just remembering what holding a pair felt like. They materialized in my hand for a while, but they still weren't quite visible until I used them.
The roses were shorter, but they were also a lot more limp and starting to change from red to white. I think it was because I wasn't focusing on them for a while and that caused them to lose some of their stability.
Oh, and another thing. In one part of the dream, I dreamt that my brother tried to come in my room, and I told him that I was still sleeping. When I said that, I think my body said it too, so I may be able to speak when I'm in a lucid dream. I'll have to record myself next time...