The Snowball Block is another simple block that can be used in making other blocks and it also makes a good alternating block in a quilt.
You will need a center square and four smaller squares. In my sample, I used a 5" square and four 2" squares - which will make a finished block of 4.5" square that is a really hard size to use in a quilt (I didn't think this through before cutting!).
Mark a diagonal line on the back of the four small squares. I'm using a chalk pencil to mark on the dark fabric. I like General's Pastel Chalk pencil and it's made in the U.S. - even better!
Place one of the small squares in the corner of the large square, right sides together, with the diagonal line positioned as shown. Stitch close to the diagonal line in what will be the seam allowance just like we did for the Flying Geese block. Repeat with the remaining corners.
Match up the corners of the small square and press. When doing the pressing first and then cutting the excess fabric off, you shouldn't have to square up your block.
Here you can see what it looks like on the back. The upper right corner has been folded open and the seam allowance trimmed. The lower right corner has been folded back in place.
This is the same step as above, just a front view.
Here is what the block looks like after it is all trimmed up.