This is one of my favorite ways to practice writing letters or numbers. We call them rainbow letters because the look so colorful and pretty when you're done.
Provide an outlined letter or number. Have the child write inside the outline of the letter 7-10 times using a different color each time. Make sure they write the letter using the proper form and in the proper order. Ex. For letter E down, out, out, out. For the younger kids I put a black dot where they need to start writing their letter each time.
Choosing a good font can be a challenge with this activity because you want the letters to reflect the elementary block font that they will be learning in kindergarten. I like to use Print Clearly from fontspace.com. It offers a normal, bold, and dotted form. It is free to download. The dotted form is especially helpful when you want the kids to practice writing specific words, like their name.
You can print it dotted for them to trace. I love it and use it daily for name practice!