It can be hard to remember and cost a lot to just go to the store and buy a card. I found a great way of keeping and organizing cards for all occasions in our home office. I love it because anytime I want to send a card, I have them right in my house and they don't cost as much.
It's a card storage/file "drawer. You can put it in a filing cabinet, but I think it is so pretty, that I sit it out for decoration as well as function. I got this for 50% off ($10.00) at the Christian bookstore. It had a ton of cards included for all occasions and dividers with stickers so you could organize it. The best thing is the cards had Bible verses in them.
I put the stickers on (in alphabetical order of course) and put the cards for the specific occasion behind the divider.
In this case, my friend had a baby boy. I went to the BABY section and pulled out an "It's a Boy" card.
The great thing is I can see when I need to pick up some more of that theme. You can get boxed cards Buy 1 Get 1 Free at Lifeway Christian everyday. When you get them in the boxes, you can file them here.
If you can't find this system, you can just buy the boxes and stack them in your office/wherever you keep office supplies so you have them on hand. You could also use a shoe box or plastic box and create your own system. I just think this was easy and pretty.