I went to a festival this past weekend and had strap buttons installed on both of my dulcimers. What a difference the strap makes! I always felt like the dulcimer was going to fall off of my lap, even using rubber fabric in my lap and a footstool for my feet. Now, I can just focus on the playing without subconsciously worrying about the darn thing falling off of my lap.
I'm glad that I paid someone else to install the buttons--I'm not a very precise or handy person.