Products recommended:
Jelly roll
2 yards light fabric
2 yards dark fabric
6.5 inch Creative Grids Ruler
9 inch Spinning Possibilities Ruler
Grips to put on rulers
12.5 inch ruler
Large Rotating Mat
You could cut a 9-inch square from template plastic and draw the diagonal and center perpendicular lines on it.
I make templates from that plastic all the time and use the sandpaper dots on it to minimize slippage.
I do put a "regular" quilting ruler on top of the template plastic while trimming the block to minimize nicking my thin plastic.