We're going to cut a two-inch strip of fabric. The easiest way I know of doing that is with a rotary cutter and ruler on a mat.
We're going to take our fabric. Take the salvage, which is this end with the holes. Match it to the other salvage. Straighten it out. The first thing you need to do is get a 90-degree angle on the fabric. You can see here, it's off. We take the line on our mat and we line up the fabric, the fold-in fabric, to the line on the mat. You put the ruler here and you're going to get a nice 90-degree angle. Then you're going to slowly cut away from you. Move your hand up the ruler and cut, one smooth motion.
Now that you've got your nice 90-degree angle that's nice and straight. On your ruler, you're going to slide it over to the two-inch marker and put it against the edge of the fabric, which is now nice and straight. You're going to do the same thing. Just roll the rotary cutter up, sliding your hand along the ruler. Make sure you keep your fingers away from the edge. That's your two-inch strip, nice and easy.
If you wanted to make two-inch squares, you'd take that same piece, line it up again against one of the lines on the ruler, cut off the salvage, that's the part that you don't really want, and line it up again on your two-inch mark. Cut two-inch squares. If you wanted to make a two by five rectangle, line it up, go to your five-inch mark. Just make sure you get it straight. Now you've got two by five inch rectangles.
This works for any kinds of squares or rectangles you could possibly need. It's the fastest, quickest way of getting your quilt going.