I have read in quilting books to resquare after so many cuts. Can't remember the number. I line a lime on the ruler up with the edge of the fabric. When the fabric no longer lines up with ruler line then I square up. How many times depends on how many cuts I need to make. I usually cut through 2 layers.

The gal in the Jordan Fabrics videos uses a barbell weight at the far end of her ruler to weight it down.

I was going to suggest this also. It really does help.

Actually I do find it easier to cut 4 rather than 2. Maybe it's the extra weight? I never really thought about it till now :)

I cut 4 layers and walk my hand down the ruler with good results. There are rulers on the market that are large squares with several cutting lines. You can cut several strips without lifting the ruler. I cannot think of brands but if I ever see one in the store, I'm getting one.

A good sharp blade in your rotary cutter also helps. You don’t have to press down so hard or go back to catch bits that didn’t cut all the way through. And what the others have also suggested(0: I get slippage some no matter what I do!

Stripology by Creative Grids and June Tailor Shape Cut. You can find the June Tailor rulers at JoAnne and can use their coupons to get a good deal. I’ve also seen them at Walmart.

I have a long 24" (?) x 5" cutting ruler with a lip on the perpendicular bottom 5" edge that hooks on the cutting mat. With my left hand on the ruler walking down as I cut, I slightly push forward so as to keep pressure on the lip, and then cut with my rotary cutter in my right hand, This lip acts like a third hand, and if you keep the rotary cutter vertical, and cut straight down , slippage is minimal if at all.

Thank you RhondaK for the video links. I tried your second link first and it was one I had viewed sometime ago but forgotten some of the finer points of the instruction. It's a good video! I actually tried cutting some twice folded fabric today, before looking at it again, and found I really did a better job with the shorter width of fabric and my square ruler. The only thing I find is I have to cut off my yardage into more manageable pieces as to use this method with a 4 yard cut is too unwieldy. I have to say, I got my cutting done more quickly too! Thank you for the refresher.

SusieQOH, I'm sorry, I just read my reply to you and I have no idea how I got an emoticon with the tongue sticking out! I hope I didn't offend you, as I sure appreciate your feedback and certainly didn't intentionally do that.