I don't think that there are any rules for this one. Pick colours and patterns that please you. If you are the 'matchy" type select four colours that co-ordinate and buy six fat quarters in that colour family remembering to vary the size of the design (each one could be different). Also try to make sure that you have some lights, mediums and darks in each of your colour selections. This is a wonderful easy pattern and no matter what colours or fabrics you choose, it will look great.