Here is a picture of the stone we laid up the other evening. I wanted to get to it sooner, but life keeps getting in the way.
The dark much shows the area we added. It's a little less than 20 square feet - not a lot - but I did in the evening after work. With set-up and clean-up we really only had a couple of hours into it. I guess I am not very speedy, but then again these are fairly tight areas, and we are mixing various kinds of stone to get the rustic look.
The mud will dry to the grey color in a couple of days...
One of the things that makes a stone job look professional is how clean it is. Sticking the stones to the wall is actually the easier part - striking the joints is where the works is...
Here is my technique for getting the joints to look "perfect":
It's an involved process, but will give you good results. I give myself as much time for this as I do for fitting and laying the stone.
If you are DIY, don't be in a hurry. Work with small areas so it does not get away from you. You can't come back later and make it right - it will be dry.