I find that it helps if I lean forward slightly so that my arm is straight up and down. That way my weight is pressing down vertically rather than at an angle.

Another trick is to go Harbor Freight and get the gizmo used for pulling dents out of a car. They are about 2.99 and come in two sizes. It acts as a suction cup on your ruler and you can hold the ruler down with one hand while cutting.

I tried this and didn't think it worked well.

Me, too, and for the same reason. Also spray baste the back of the ruler so that it grips the fabric.

Baste spray is only messy when you spray the ruler. It is sticky, so I take a scrap of cloth and rub it over the ruler back, test it, rub again, test it until it is just right.

I have just purchased a pack of Grip Strips from Guidelines4quilting.com. They let your ruler slide over the fabric but when you push down on the ruler to cut they grip really well. I love them.

Just wondering how tall your cutting table is and where the actual top of the table hits your body so that your arm can be in a straight up/down position, Thanks

I have clear plastic dots that I got at Joann's. I put one in each corner of all my rulers. they work great!