For my blocks, I went to Lowe's and bought a 2x4. It gave me lots of extras for more projects and I had plenty for this one. I had Lowe's cut it for me just because it was easier but I think they charge 25 cents a cut, so you could do this cheaper if you cut it yourself.
I cut the 2x4 every 3 inches until I had five blocks. Then I sanded them down. (I love my sanding block pictures below. I used to go through sheets and sheets of sandpaper until I discovered these. They last a long time!)
Then I painted them. I hated my color of green and I couldn't get to the store, So I mixed it will black paint until I had a dark green.
Then I painted the blocks and let them dry. I then cut blocks of shamrock scrapbook paper to fit slightly under the size of the blocks. I decoupage the scrapbook paper on and meanwhile I painted my letters white. When everything was all dry, I hot glued the letters onto the blocks.
I picked these letters up from Hobby Lobby. There were 77 cents a piece and it came with four letters in each pack, so you can save the extras for future projects.
Here is how they turned out. It is supposed to say Lucky but my little girl absconded with the Y block. Oops and there goes the C.
I really like these. They are simple and a cute decoration without having to find a place to store something huge!