You should start with BOTH squares the same size, 7/8" larger than you want your finished one to be.

HST's and I have a love hate relationship. I give up on those being perfect ;)

I also make my squares a little bigger and then square them up after I cut them down the middle. I know this is more work, but I have more accurate half square triangles.

Try a product called "SQUANGLES" it is awesome...comes in packages with various sizes and it is an iron on transfer that works wonders! sizes from 1/2" finished to 4" finished...hope your local store has it...if not Suzy Q in Bandera, Tx has them and I bet she would mail them to you....

stitch a thread to the right of the drawn line, this allows for turning...

These are not half square triangles so that is why the 2 pieces are not the same size. It you go to Bonnie Hunter's Celtic Solstice quilt she talks about the flip and sew method,also some info on her new leader and ender project.
Another way to do this is with inklingo. Here's the link for that site:

http://inklingo.com/shop/lucy-boston...63467c9dae521b
Good luck, I hate that flip and sew method

cindy

I make mine a little bigger and then cut to size...

this works for me also.

I agree! Squares should be same size. even if making flying geese or snowballs the width of the pieces should be same. Also you need to sew 1/4" on either side of the diaginal line if you do 1 line or you can use a ruler that marks each sewing line. Yes 7/8" is harder to cut the an even inch but is the amount that you need to add over the size of the finished block to get the correct block size. Making block larger means that you have to cut block down and means more work.