I'm not a big fan of measuring. I avoid it whenever possible, relying on the eyeballing method instead. When I need or want something to be more precise, I use my Centering Ruler.
I love it. It is so quick and easy to use. Simply put the zero near the center of your project, then make small adjustments until the edges are both the same distance from the zero. No real measuring, no making marks, no stress if the item is a nonstandard size.
Here's the finished card. The sentiment is perfectly centered.
Cindy deRosier has a masters in Education and taught for 11 years. She uses that experience to blog about kids crafts and family-friendly educational travel. She is the Editor of Fun Family Crafts, a website with over 12,000 kid-friendly craft tutorials. Cindy is the co-author of "What Would Jesus Patent?" and does freelance writing and designing.