Quilting rulers come in all different sizes and shapes. Heather Thomas will teach you how to use them properly by explaining what all of the different hash lines on them are for as well as the diagonal lines.
String Block Quilted Coasters/Mug Rugs --small quilt projects are a great way to explore creative avenues just a teense...as in this tute http://greenwich-8.blogspot.ca/2012/02/colour-studies.html. For half square triangle designs I love the Triangulations DVD! sample sheet https://www.bearpawproductions.com/userfiles/file/Half%20Square%20Sample%20Grid.pdf Quilt Pro has a similar product.