Experimenting with gluten-free flour

At Christmas, a new friend came over for tea and cookies, and I was horrified to learn she eats gluten-free and that I had only one type of cookie she could eat! I hope to have her and a few other friends over for tea again this spring, so I decided it was time to experiment with making some gluten-free cookies. I also wanted to use up these pastel M&M's so that I'll quit eating them, so I made gluten-free M&M Easter cookies!

Another friend had recently told me about this King Arthur gluten-free flour, and while a bag of it isn't cheap (about $10), it was a must.

I used a favorite sugar cookie recipe and quickly plopped some M&M's on top after they baked. All the online reviewers of the M&M cookies said it's hard to get the candies to stick, and that was indeed the case. So I made only a few of the "bunny ear" cookies and just went all lazy on the others.

When my little neighbor friends came over for tea yesterday, I got them to be my taste testers, and they liked the cookies, although both of them promptly plucked out every single one of the M&M's, ate the cookie, and then ate the M&M's. Any tips on baking with gluten-free flours? Any recipes I should check out? Advice would be most welcome!