The rotary cutter means that you dont have to use templates and here are some simple rules that you can apply throughout your patchwork:

On the Flying geese fast no-waste method you just need to add 1 1/4″ to the finished size you need for the larger square so for 4″ you need 5 1/4″ and then 7/8 to the size of the smaller square – so again you are right at 2 7/8

and if you want to enjoy the video on this click here:

The other magic numbers for rotary cutting are as follows:
For a plain square you add 1/2″ so 4″ finished becomes 4 1/2″

For a half-square triangle we now add 1″ – so cut 5″, – and once sewn trim back to be an accurate 4 1/2″ before sewing

and for quarter-square triangles we add 1 1/4″ (as per the flying geese) and pay attention to the seam allowance we sew!