Here is the card that I designed for my sisters 50th Birthday.
Front of the card:
Inside of the card:
The card is 5.5 x 4.25. The card base is black. I used a piece of 5.25 x 4 card stock, and embossed it with the Happy Birthday Cuttlebug embossing folder. The 50's were cut from Lyrical Letters, cut at .75". For the balloons, I used Sookwang double sided tape on white card stock. I then cut the balloons from Stretch Your Imagination Cricut cartridge at 2.5". Since the card base was black, for the inside I simply added a 5.25" x 4" piece of white card stock, a few more balloons, and another 50.