Needing some basic information
I had an awakening when sewing along with Edyta Sitar's mystery last year. I just loved the basic way she made her units: For HSTs, cut squares, cut in half diagonally, sew together. For QSTs, cut squares, cut diagonally twice, sew together. My problem is, I can't find the basic information I need, which is, how to figure out what size square to start with when making these units. All the information I find when googling involves less straightforward methods, like making multiple units at a time, over-sized units for trimming down, etc.
Can anyone tell me how to determine the size of square to start with based on finished unit size, for HSTs when cutting in half diagonally, and for QSTs when cutting twice diagonally? Is there a formula? Thanks!