Christmas card and a question

So I stamped an angel image out last week, and just didn't get around to making a card for her to go on plus I just wasn't really in a stamping mood *GASP*! Lol, so today I thought I would make a card for her to be put onto and I thought the Christmas holly flourish stamp would look really nice as her background. So I used my Versamark ink, then used some fine gold embossing powder, then used my heatgun (which I am told there is a bettter one out there) and then I noticed something I don't think I noticed before. So here is my question to you, how to you prevent your cardstock from curling over when you are embossing??? I was happy with how my card turned out, but was sad that the card had a curl to it and I didn't have the heatgun on the card too long either.
My other question to you all is what else should I add to this card, it looks like it is missing something....any ideas??

Hugs,
catherine