yeah, the Ricky Tims is made from stripe sets and you really don't fussy cut. And he has you draw out your template shapes to suit you--that is where you have to be careful not to set yourself up for Y seams!
He gives you the measurement ratios to make the kaleidoscopes different sizes--with the larger ones you definitely need more fabric stripes. You do the strip sets, cut your templates from them (he gives you ways to do that so it works), then sew together and you get a "pie", then by sewing those Pies (12 opposing sets) you get that kaleidoscope, add the setting triangles and you have a square.