Wrenkins, starch is optional, not necessary. It can be helpful to keep your fabric/blocks from stretching particularly when you are going to be dealing with bias edges which can be difficult to manage if you don't handle them carefully. But do be mindful that too much starch can make things awkward to. Finding your own preferred method for making HST's might take you a few "goes"....try some different methods and while practising them always pretend you need bigger HST's than you really need......that way you have plenty of trimming room to cut your HST down to the perfect size.
You'll be whacking 'em out in no time with not a second thought to it!!!!
gasp...Lowie...you cut the squares into triangles and then sew them together......you actually voluntarily cut and sew triangles together......really? I pay homage to you....Lordie, even the promise of a very fine Shiraz would not see me happily cut and sew triangles....eek....shudder....it's all coming back to me......eyes misting over, perspiration beading my forehead.......