Just wanted to show a couple more layouts for the Snail’s Trail block. I am sure there are many more, so as not to let a single image limit our possibilities. I can remember when I first taught my children to sew. When they looked at a pattern in the pattern book, the only thing they saw was the actual picture. It took a lot of discussion for me to convince them that they would be using fabric that they chose and making the garment in their own style.
The first image shows the block as an “economy” or “Square in a Square” block layout. The blocks are done in a positive/negative alternating arrangement. This doesn’t look like a Snail’s Trail at all, but the cut pieces are the same.
And this is a fun layout and requires two different blocks that are mirror images of each other as well as particular attention to color layout. 
Do you have a favorite layout for the Snail’s Trail block?