“Fix-ups” are a great way to have students identify and correct written errors, which can then carry-over to editing their own writing. These winter themed fix-ups focus only on capitalization errors. You can print copies of this language therapy worksheet for individual work or write the sentences on a board for a group activity.
When I have students come to the board, they say what the error is, WHY it is incorrect, and then fix it. For example, “The ‘t’ needs to be capitalized because it is at the beginning of the sentence.” It takes some prompting for the reason at first, but after a few times, they remember to include it. I find that by explaining the errors (repetitiously and aloud) the students teach each other the rules!