Use It Up - Printed card bases

I got a bunch of these printed card bases pretty cheap, but have been surprised to find myself struggling to figure out how to make use of them. I finally decided to use a bunch of them to make some quick and easy Valentine's Cards.  I know it's a long way until February, but Valentine's Day snuck up on me this year and I didn't get many cards done.  This way I have a head start for next year.

I decided I'd use hearts cut and embossed with my Spellbinder's dies and glimmer paper in colors that coordinated with the card.  I figured they'd make a decent focal to which I could later add some stamped sentiments.  My first attempt, however, didn't look that great.  It was clear I needed to mat them to help them stand out from the background.

I had this turquoise mat I had already cut and embossed with a Spellbinders die, but found it just didn't do what I had wanted.  I needed a lighter color with more contrast, and I really liked it better when I used 3 hearts instead of just two like I did here.  For the rest of the cards I used white mats, and was much happier with them.