You know how when you cut fabric for a quilt block from a larger piece from your stash you very often cut it a little bit too big, then you iron it, and then you cut your piece to the exact measurements you need. Or when you're foundation paper piecing you cut a generous piece of fabric that will definitely cover the bit in your pattern that it should cover and then later you trim the excess away. When you do these things (I do, it's very handy, you don't run the risk of accidentally cutting your fabric too small), you end up with waste. Very pretty, but useless waste.
Usually I find that no problem, it's just the way it goes. Sometimes you want to do things differently though. For instance when you only buy fat eighths of the Chicopee fabric line (like I did, to save a bit of money) or when you would like to start cutting into your Liberty Lifestyle fabric and don't want to waste a thread.
My pile of Chicopee fat 8ths
My Liberty Lifestyle fabrics, too pretty to waste
For that situation I came up with instructions and measurements for a little quilt block that is usually made by foundation paper piecing. These measurements give you no waste, except for possibly a little fluff that you cut off at the end to square up the block if you need to. You end up with a 6 1/2" block (6" finished) that doesn't have any fabric running on the bias.
This is what you need to do. First iron your fabric. If you have only fat eighths it is not such a task, otherwise drag your yardage to the ironing board and iron the corner that you're going to cut from. For the center cut a 3.5"square. For the triangles around the center cut a 4 1/4" square and cut it on both diagonals to create four triangles. Sew these triangles to the center square using a 1/4" seam allowance. For the outer triangles cut two 4" squares and cut each diagonally once to end up with four triangles in total. Sew these triangles to your block, again with a 1/4" seam allowance. Check if you need to square this up to 6 1/2 ". Done!
This way you only use a little bit of fabric to end up with something lovely! Hope I helped someone getting over the fear of cutting into those precious fabrics (fyi, my Liberty Lifestyle is still untouched...)