I gave some thought to this as someone else has expressed concern. I sat down last night and figured this out.
If you use a 6 1/2" template you can add an inch and a half and cut out a 9 inch square and then fold it in half so it is triangular. Cut down the fold and you have two triangles and will have alot less waste. The middle section will still need to be rectangular and you will need to cut it the 9" x about 5" to have enough room for the template to fit.
I am going to show how to recycle the leftovers. You can cut larger like I do and have a larger piece to recycle or you can figure out how much is just barely enough and then you will have a little bit of scrap to throw away.( 1/2" to 1" wide).
I like to cut larger because i have another triangular piece leftover from the swatch(not the cut in half triangle) and i use it to make another block. I don't have pics ready to show this yet but I will try to post this tonight or in the morning. We don't throw much away. Yes you will always have some leftovers but there are ways to use them.
This is for those who do want to do miniatures and have asked me how big to cut the swatches. You could use the same method above if you like but this is how we do it.
When I use a 1 1/2" template I cut swatches about 2" x 3" to make my blocks. Then I pull apart the leftovers and turn them to use for the next block.
When Dorothy does these for me she measures and finds the smallest number to cut the swatch. Then she sews and cuts the 1 1/2" blocks and sets the leftovers aside. Then she pulls apart the leftovers and resets them to sew them again and cuts out 1 1/4" blocks. Then she repeats this and cuts out 1" blocks for me.
She does these in an assembly line fashion. I use the 1 1/2" for hotpads and bookmarks and sometimes checkbook covers. The 1 1/4" I use for bookmarks checkbook covers eyeglass cases etc. The 1" I make 3" quilt blocks and keychains and magnets. And I use these 3" blocks in sampler quilt hotpads.