My problem with making quilts for babies and children is that by the time I get one finished, they've outgrown or moved on to another interest! I'm not a fan of themed quilts anyway, so I tend to make color-controlled scrappy quilts with solid sashing or background. Right now I'm hand quilting a 60 degree triangle baby quilt that is 50 shades of blue solids, the first all-solid quilt I've made. It is throw size so that it can be used for a long time.
The next two boy quilts that I make will have nine-patches in the block designs. I am collecting men's dress shirts on sale day at Goodwill to make the central 9 patches and then order some solids and prints to finish the blocks. IMO shirtings add lots of interest to masculine quilts.