The best way to build up your own supply is to recycle, recycle, recycle. Put on your nerd hat at parties and fold up the used tissue paper for future use. Keep bows and nice ribbon and obviously hang on to those gift bags. Shop clearance and heavily discounted items post-holidays. And to get yourself some basics, shop your local Dollar stores. If you do this for a year or two, you'll have a bunch of stuff that you're not sure where to store or how to organize.
It'll then be time to branch out into some drawers or totes of some kind. I like the plastic three drawer towers personally, but any type of storage device will do. You can get creative with this if space and money is limited. I am fortunate enough to have some extra space in my son's closet, so that is where my little plastic drawer shrine is located. Labels on the outside of the drawers are the icing on the cake and make anything you need right at your fingertips.
Not only will you feel calm and organized when holiday, party or craft events come around, but you'll be saving yourself money as well. If you do decide to splurge on some nice storage drawers they will pay for themselves after just a couple of times that you DON'T have to run to the store and grab a last minute gift bag, bow, card and tissue paper (easily $10).
Here are some pictures of my mini store. I've also got my baby supply drawers right next to them. And Austin decided to make a cameo appearance in the photos too! Cute boy.
I don't know if you can see inside the second drawer from the top on this picture, but it's where all my bows and ribbon are stored. I came up with a great way to store all those fancy thick ribbons you get on packages. Take an empty wrapping paper tube and cut it to the length you want. Then wrap the ribbon around the tube and secure it with tape, a staple or a rubber band. It keeps all those ribbons looking like new and makes storing and reusing them a breeze.