Maybe I'm a bit late adding to this topic but would like to mention some of the tips I picked up from a neighbour who is a macon. Mix is better loose than dry, it sticks much better. Try throwing the mix from your trowel into the joints rather than pressing it in, over a couple of square feet and then remove the excess ith the edge of the trowel. If you place a board or a piece of plastic sheet under where you are working you can recycle all of the mix that falls off (you will need to add extra water to it), The chaux is ready to brush when you can just press a fingernail into it, if you are getting wire brush marks it could be because the surface is not quite dry enough or you are being heavy handed. After wire brushing the excess you can "paint" over he chaux with a wet paintbrush. This will make the larger grains in the sand shine. finally, if you have to leave a part mix in your auge for any reason, add more water and keep it in the shade, it should then rework when you come back to it rather than going hard.