Ideas for grandsons quilt using 25 fat quarters

[Sonic]

I'm going to jump right in and suggest that you do a D9P (disappearing 9 patch) - it's quick, looks as if you did a whole lot of work on it, and is a good piece to showcase some of your larger print pieces.

Disappearing Nine Patch Quilt Block Tutorial | Always Great, Always Free Quilting Tutorials

Have fun - I like the fabrics you've chosen.
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Oh, welcome to the forum from NW MO, and remember you can make your squares in this quilt any size you want!!

I second this idea. I just finished a very similar quilt called Slice Of Life
https://www.missouriquiltco.com/shop...-quilt-pattern
and the only difference is putting a neutral color between all the blocks first.
I used fat quarters for the quilt top below and cut them to the size I wanted. (9") I'm a newbie also and found that the top went together quickly and the big blocks made it easier to make sure I sewed them together correctly.