Making your own Halloween greeting cards can be a fun exercise for the entire family, but especially for the kids.
There are several ways you can make these cards. One way is by downloading Halloween designs from the Internet and pasting them onto blank greeting cards. In addition, there are also templates online which you can print out and have your kids color for their cards. There are quite a few websites that have collected Halloween designs in the public domain that you can use for free and do anything you want with them.
Another way, and more fun for the kids, is to simply use construction paper and crayons and let them be as creative as they wish. 
They can draw pumpkins and spiders; bats and witches; ghosts and goblins, whatever their hearts desire. Then cut them out and paste them onto black construction paper. They can write their own greeting inside and send the cards to friends and relatives.
The kids can also use pictures taken in their Halloween costumes and paste them on the front of a blank greeting card and write their own message inside. Think how proud their grandparents will be once they receive these cards in the mail.
Halloween stickers can also be purchased at your local card store and used to decorate the envelopes.
If you or your kids are familiar with Print Shop, you can make any type of Halloween card you choose. Print shop allows you to place images and text on the front, inside and back of the card. Your kids can make wonderful and colorful cards using this software.
Considering the cost of postage these days, perhaps you may wish to have the kids draw their greeting cards and you can then scan and email them to relatives or friends as well.
Whatever method is chosen, kids will have a great time creating Halloween greeting cards for friends, relatives, and mom and dad too. Save the cards for your scrapbook, so that you can recall the wonderful memories of Halloweens past, present, and future.