I would like to play - but my fabrics have all been washed with unscented laundry detergent.
As far as doing the previews - you might consider using a 4.5 inch square cutout instead of a 5.0 inch cutout - because 4.5 inches will be the finished size (unless the squares will be cut smaller).
It is definitely worth doing a preview - not all "novelty/conversation/I Spy" type prints work well with that size square. (Ask me how I know!)
For fussy cutting, I cut a 5-inch square of template plastic - to mark the "seam allowance" - I did one of two things - I drew a 1/4 inch line to mark where the stitching line would go - or I taped 1/4 inch masking tape along the edges - so that I could "see" what would be showing.