I think you've got it.
(and I'm assuming the blocks are 4" FINISHED.)
You would join the 4" blocks into a strip that would be the length of the panel.
If the panel size is not evenly divisible by 4" (let's say it's 26" x26" finished), then you could put a 1" filler strip (cut 1.5) at each end so you would get to the correct length.
Make 2 of those and attach them to each side of the panel.
Same for the top and bottom. You'd make a strip of 6 of the 4" blocks, add the 1" coping strips on each end, and then another 4" block for the corner blocks.
The coping strips could be a coordinating fabric(s). As long as you're using it in all 4 corners in the same place, it will look like it's part of the design. You could do a more involved design - let's say use only 4 blocks, which leave an additional 10" to fill. You could use 2" spacers between the blocks. As long as when you're done, you've got a 26.5" strip (excl. the corner blocks).
Also, if your blocks are directional, take care when making the strips so they end up orientated the way you want when attached to the panel.
I always prefer to put the sides on and then top and bottom (especially if I'm not mitering).
Does that make sense?