Before you buy a lot of rulers or stash, it helps to know what type of quilts and colours you like. I know that almost all quilt blocks that I make end up at 12 1/2". As a result a 12 1/2" ruler to square up my blocks before assembly is really useful. I also know that the components to make a 12 1/2" block often include 4 1/2" or 6 1/2"sections so I bought those sized rulers to help me square up blocks. You could use your 5 X 12 ruler but having the exact sized ruler really helped me. The biggest mistake in building my stash was in buying too many brightly coloured focus fabrics. If starting a stash, I would advise investing in blenders, tone on tones and "quieter" fabrics that will be needed in your quilts. Before I really quilted, I just didn't understand just how important these "boring fabrics" would be and just how much of this type of fabric you would need to complete a quilt. I also didn't realize that you need a selection of light colours to balance the deep intense tones that I favoured. Put the word out in your community that you are a quilter and you may be surprised at what "gifts" may come your way when family is cleaning out grandma's sewing room. I have been gifted with all sorts of fabric just because people know that I love to stitch. I was even given a couple of good sewing machines this way. Happy fabric and ruler collecting!