Here is the sign I made! As you can see, I sold regular lemonade for $1 and soft frozen lemonade for $2.
And as you can see in the second picture, I stapled the sign to some cardboard because it has been a little windy recently.
The left picture is all the lemons I squeezed (it was hard work! haha), and the right picture is a lemon. The bottom is the juice I got from 8 lemons which I had bought at a produce market.