MTS

It's just a variation of what's called commonly refered to as the Warm Wishes pattern.

You can devise your own pattern by determining the basic FINISHED sizes of the components.

From the picture, I would make the following assumptions:

Boot blocks - the small boot squares are half the size of the larger boot blocks.

Sashing strips - the width of the three strips together equals the smaller square, so to make life easy you want a number easily divisible (and measurable) by three.

For example:
FINISHED small square = 6" (cut 6.5")
FINISHED large square = 12" (cut 12.5")
FINISHED strip = 2" (cut 2.5" x width of fabric)
Three strips would be sewn together and then subcut into 12.5" long (UNFINISHED) units.

Layout out the sections and sew together.
That part should be relatively easy - it's pretty straightforward.

I think the sizes you choose should depend on your focus fabric.
If it's a large print (like a Kaffe floral), then the 12" size would be fine.
But if it's a very small print, you might want to take the sizes down a bit.

Here are some other measurements that would work:
FINISHED small square = 4.5" (cut 5")
FINISHED large square = 9" (cut 9.5")
FINISHED strip = 1.5" (cut 2" x width of fabric)
The three strips would be sewn together and then subcut into 9.5" long (UNFINISHED) units.

Here are measurements for a much smaller version:
FINISHED small square = 3" (cut 3.5")
FINISHED large square = 6" (cut 6.5")
FINISHED strip = 1" (cut 1.5" x width of fabric)
The three strips would be sewn together and then subcut into 6.5" long (UNFINISHED) units.