It's the first time ever that I manage to complete any of the tasks. Happy I did it!

Here are the parts of the dream where I do them:
"Then, I remembered about the two basic lucid tasks I had read on the forum. The first one was to hit a DC with a snowball. I saw a friend of mine, so I decided to start a snow fight with her, despite there wasn't any snow. I looked at my hand and tried to make a snowball appear. She noticed what I was doing, so she dug her hands into the wall of chalk, made a snowball out of it and threw it at me. It behaved as though it was snow, so I gathered as much as I could and threw it back at her, without hitting her. This whole thing repeated a couple of times until I finally hit her. She looked at me like: "really? Was it that hard to aim well?"

Then, I went for the second task, giving a DC a lump of coal as a present. I entered my house and saw some family members. Again, I looked at my hand and tried my hardest to make some coal appear, but it didn't. I must've been at a low level of consciousness, because the dream wasn't behaving the way I expected it to. Regardless, I wasn't willing to quit, so I approached my grandma and held out my empty hand to her. She reacted as though I had a gift on my hand, and when she held it, something appeared on her hand. It was cube-shaped and wrapped in paper, so I assumed it was the coal lump. She unwrapped it and it did look like coal, but she opened it as if it was a box and took a necklace out of it. I was taken aback."

Here's the DJ entry, in case you need to check it all: Paragliding - Dream Journals - Lucid Dreaming - Dream Views