True Grip dots work really well and they are very thin. They have more of a rubbery feel.

I've tried hot glue, sandpaper dots, all kinds of stuff, and finally developed a technique of holding the ruler down with my thumb and my pinky finger going over the edge of the ruler, and my other 3 fingers pressing down on the ruler. This worked great.

Until I discovered Steady Betty strips. Holy moly, those things are awesome. They're about a quarter inch wide and 4 inches long, and I cut one in 3 pieces and stuck it on my ruler. That sucker doesn't go ANYWHERE anymore. Of course, now I have to pick the dang thing up, I can't slide it across my fabric to make the next cut.... :D

ArtsyOne has the ticket. Go to Wal-Mart and pick up some Elmer's rubber cement. Its clear when dry and you can peal it off with your finger if it gets dirty and it's gone. It's in the school supplies section and it's CHEAP. Doesn't take long to dry

I prefer a different method entirely. I use a June Taylor 1/2" Shapecut. If I am making 2.5" strips, I can make 4 accurate cuts without moving the ruler. Oddly enough, although the now deceased former prexy and teacher for our guild introduced them, most memebers of the guild don't use them and never have. This is really a matter of taste.

I find the little rubberised slip dots to be the best to apply to the rule. Either that or cut out little squares of sandpaper and stick them to the back of your rule in a few places.

I am a new quilter also. Only on my second quilt but also had the problem with the ruler sliding. I bought the sandpaper dots and the work well. You have to make sure you put enough on the ruler though.

I use invisigrip on some of my rulers and have not had any problems.

this is my favorite, works so well you have to lift the ruler to move it to a new position

I love True Grips. They are rubberized clear thin circles so you can still see through them once they are on the ruler. They work great in preventing the ruler from sliding. Sandpaper dots are also nice but they do obstruct your view since they are not see-through plus they do wear down after a while :)

I'd always used these sandpaper dots.
A friend gave me invisigrip and I hated it; did not work
I'm back with my sandpaper dots
You can get them at Joann's