First I drew several sets of upper and lowercase A's on his chalkboard.
Then I gave him a small cup of water and a few quips and had him wrote over the letters with the water "erasing" them. He was so proud of himself after every set he did. You could really do this activity with any letter or number
The most important part when doing this activity with your preschooler is to make sure you stay as positive as possible even when they are not tracing things great. Positive reinforcement goes a long way and will help them so much more then telling them everything they did wrong.
We have a few more activities planned for today. I will keep you posted and hopefully give you some good ideas for teaching your preschooler.