I do a lot of straight line quilting and mostly do QAYG....my blocks are usually around 15" and I connect them with narrow sashing...you can do larger sashing but you have to sew in batting between. I don't mark...I use my Bernina walking foot for measurements....I start by finding the center of the block and use blue painter's tape as my first measurement...just follow that line with the walking foot and after that can just use side of walking foot for 1/2" or inside of foot for 14" ...or you can just keep moving the blue tape if you wish. Jacque Gerhing (Craftsy videos or has books) is an excellent instructor for modern line methods.