I used some green DK yarn and a 3mm hook, I think this could be a case of use what you have and it will probably be fine. Each leaf only takes about 15 minutes once you get the hang of them so you can afford to experiment.
You can make a garland as long as you like with this pattern, the leaves could be different shades of green to use up your yarn stash, you could make little red pom poms to use instead of buttons, or circles of felt.
I also think just one leaf with a plain card gift tag would be SO sweet on a present (I might do that next year, this year I've made these paper napkin poinsettias for gift wrapping)
Don't forget to check out the other Pinterest inspired projects from these other amazing blogs, just follow the links below.