The challenge was to improvise a block. I believe the idea was to do something modern with bright squares on white and I like some of those and eventually did one -- sort of -- but was not at all happy about it as a block. What I did first was this one which doesn't look improvised at all. But it was.
I started with four 5x5 charm squares, all batiks, two were blue with purple in them -- they were different batiks but the colors were the same intensity -- the other two were pink with purple and a pinky-apricot. I sewed them together and then I cut off half of each of two sides, switched them to the other side and sewed them together and then I did the same with the two sides I had not cut. So I then had a different block which I then cut diagonally corner to corner each way so I had four pieces. I switched them around and sewed them back together. Then I cut the four corners from middle seam to middle seam and switched them and sewed them back together. That produced the inner block. If I had done some different switching it would look a bit different.
By then the 9-1/2x9/12 inch block that resulted from sewing the original four charms together had shrunk to 7x7 and I needed a 10x10 inch block, so I added the border which is a third blue batik.
This was fun, a little bit labor intensive, but then isn't all quilting somewhere between a little and very, very labor intensive? Last spring I purchased several packages of batik charms about 120 total and all different. I have a stash of batiks collected for a few years so I could make a complete quilt as I made this block, it would be one of those multicolored creations that really fascinate me. I also like projects where I can do a block or two a sewing session over a longish period of time until I accumulate enough for a quilt. I think I have just talked myself into making a quilt constructed in this way using only those batiks. Check back in 12 of 18 months for a progress report.