Many years ago my kids and I sat down each year and made Christmas cards together. As the kids got older their enthusiasm faded and now its just me who makes the cards each year. Making your own Christmas cards is not the most frugal way to send cards. I could buy cheap cards for a lot less than the cost of card making supplies. Handmade cards do seem to be more in the spirit of Christmas than store bought cards. I was surprised to hear that some people have kept all my cards from over the years and look forward to receiving them each year.
There are hundreds of ideas for card making on the web. Cards can be as simple or as complex as you like. Have fun making your cards, involve your kids. If your kids want to help out remember its the thought that counts and don't worry if the result into perfect.