Here's a tutorial for an easy peasy autumn card using materials I unearthed during my move. I'm betting you guys probably have all the supplies to make it too.
Here's what you need to get started: a blank notecard (you can easily cut a square of cardstock if you don't have a readymade card); scissors, colored paper; metallic gold or silver pen; and a glue stick.
First, I cut many little leaf shapes out, and then colored one side of each leaf with a gold pen.
Once you have all your leaves colored, draw a simple tree shape and start gluing. The more randomly you glue the leaves, the better it looks.
Next, I took an old paintbrush and some Mod Podge (you can also use plain white school glue) and painted a thin layer over all the leaves to help seal them in place and add a bit of luster.
And that's all there is to it! Addressing the envelope with the same metallic pen is nice, and you can also embellish the envelope with a leaf or two if you wish.
This particular card has already been added as a "thank you" to someone who bought two brooches from my shop. I try to include handmade cards with all my orders.