First off; no ruler is completey slip proof. I don't care what anyone says, human error always wins. Non-slip products do help and there are several products out there.
The trick to rulers is finding one that works for you. Are the markings easily read? Does it feel good in your hands? Is it too bulky or too small for the project you are doing? You should have several sizes to work with.
I've used the non-slip kitchen rolls. I can just move the piece under the ruler and cut. It's cheap and it's okay if I accidentally cut it. I don't like stuff on my rulers as I find it distracting and harder to see the marks.
The basic idea of the "Shape Cut ruler" is to place the ruler over the fabric aligning the edge with the dark line and cut the strips.
I put the edge of the fabric on the second line so the cutter doesn't get stuck in the grooves. I have 3 fat quarters folded over creating 6 layers of fabric. That means the ruler needs a little more stability other than my hand hence using the non-stick kitchen stuff.
The hardest part about cutting strips is knowing your math. It's easy to lose your place if you don't know the numbers to put your cutter through. 0, 1.5, 3, 4.5, 6, 7.5, 10 is for 1.5 inch strips. If you did it right, here's what you get:
The nice part about this ruler is that you can now make squares. I align four strips of fabric across, put the ruler on them and cut.
Truthfully; I can cut much faster than the Go! Cutter this way. I just feel like I have extra steps with this product. I still haven't opened my box. BTW, if you are cutting strips with the Go! cutter, cut 8 inch wide strips to put across the die.
I also cut at an angle. I don't know if anyone else does, but I just align the ruler up and cut:
Now back to cutting never ending strips! Only about 20 more fat quarters to go!