There are about a hundred versions of these out in blog-land. Here's mine:
I took a 2x4 and used a miter box to cut it into different sizes. I think the tall ones are 6 inches, and the shorter ones are 4 inches. If I did it again, I'd probably include a third size in there somewhere.
After cutting, I sanded all sides and painted the back and sides creamy white. Then I cut my scrapbook paper to fit, applied a thin coat of Mod Podge, and smoothed my paper on. I used an emery board to sand the paper down to the blocks.
When I made these, I didn't have a craft cutter. Thank goodness I am now the proud owner of a Silhouette, but it is possible to create great looking letters without one! It just takes a little more time and work. Here, I simply printed the letters on cardstock and cut them out with an Xacto knife. Then I applied a thin coat of Mod Podge on the top of the scrapbook paper (both to seal the paper and to apply the letters), then carefully placed them where I wanted.
A few ribbons for embellishment, a paper flower (from this tutorial) and button hot-glued on, and voila! Cute Spring blocks!