What I have done is make up the cookie dough and then on a cookie sheet I've lined with wax paper, I just drop the cookie dough in the appropriate amount, just as if were going to bake it.
Actually though, you can get many, many more cookies on one sheet because you are not baking them and they won't spread out on you.
Then I take the loaded cookie sheet and put it in the freezer for at least 20 minutes, no longer than 1 hr.
The cookie dough has hardened and can easily be peeled up from the wax paper and thrown into a freezer ziplock bag. Then just seal the bag and throw it back in the freezer.
It is a good idea to label the freezer bag with the cookie name, temp to bake at and time to bake - or you could reference the cookbook it is from and page number if needed for baking/decorating followup.
I have also frozen rolled cookies, I just place the rolled and cut cookie shapes on the wax paper lined cookie sheet and treat them the same way as described above.
:-D