Here's a CAS card using geometrical shapes as the design, in this case hexagons !
I die cut a number of printed papers with a hex die (Stampin'Up). I then took a 5 x 7 white card blank and cut a slightly smaller matt out of white card. I arranged the hexagons onto this matt until happy and then stuck them in place.
The decorated matt was then matted onto more printed paper and the design applied to the card front on foam pads.
The sentiment (Inkadinkado) was stamped on more white card in Versafine onyx black, trimmed and applied on more foam pads to finish.
This meets this weeks Challenge over on the 'Less Is More Challenge Blog' whose subject is 'Geometric'