Sometimes it is fun to begin a project like a coaster with a magic circle, because you can tighten it up after completing the first round of crochet, leaving a solid circle or the smallest possible hole.
You can make a magic circle n 3 easy steps:
1. loop yarn over end
2. Insert hook into loop – notice you are wrapping the second loop around the yarn.
3. Pull loop through for magic circle, and work around the circle.