There are many, many choices of lovely notecards with blank insides on etsy.com. Buy a handful of different sets and then mix them up into sets of 5 or 6. Make as many sets as you need for all your gift-giving occasions. Put each set into a small printed paper bag or colorful envelope with a bow and you're ready to go.
I made a Pinterest page of a zillion choices. Each one links to the page where you can buy.
Don't forget to keep one set for yourself... they are perfect for thank you, congratulations, or sympathy notes.