Buy pretty blank cards – I always look in the dollar section at Target, these ones were only $1 for 8! Then buy a pack of stick-on letters, these are Thickers by American Crafts. You can buy them in the scrapbooking section of craft stores.
The hardest part is spacing the letters and getting them centred on the card. I have to admit I struggle a little with that!! And there you have a pretty, personalised card for a very reasonable price.
Of course you don’t just have to write a name. Sometimes I use numbers for the age, or create whatever message I need. Get creative with it!