The process is pretty simple. There is no special way to do it. Your brush strokes don't affect the finished product so you can apply the clear nail polish anyway you want. Going over a finished area again, doesn't impact the finished project either. It's a pretty fool proof project.
I had done this before with the Haunted House Dollhouse kit. The Haunted House kit does not have this many windows though and they aren't silk screened like these, so this is what I've noticed so far. The frost goes on differently for each window so you will have slight inconsistencies with each one. This is most noticeable now because of the dark background of my work table. I believe that the silk screen design on the windows is causing this. For some reason the printing of the silk screen design changes certain areas of the acetate causing the clear nail polish to have varying effect and therefore the inconsistency. In some windows it's more noticeable than others. The amount of nail polish used doesn't seem to change the effect either. In other words, your windows will frost as they want. There is very little you can do to control the outcome.
The Beacon Hill window panes are pretty large and most of the windows will be covered with trim so don't worry too much about the inconsistencies along the edges of the windows. Some of these windows are so large that they will have to be trimmed down so they fit the openings. This will reduce the amount of variation seen between them. I'm still brainstorming what can be done to even them out a little more. I thought of maybe using a nude or sheer nail polish over the clear to smooth out the variations but I won't know if it's needed until I see the panes in the actual window openings and with the window treatments behind them.
Overall, I like the effect that the stained glass frosting made on these windows. Unfortunately, I'm having a hard time imagining what the end result will look like on the dollhouse itself and this, we won't be able to see just yet. After all, I have an entire Beacon Hill to assemble first.
