Here's how I did it!
The first step was to install the bead board wall paper. I bought the chair rail from Home Depot and my Dad came over with his miter saw and did the cuts and the installation. I then gave everything, including the wallpaper, two coats of white paint to make it all uniform in colour.
I read and pinned on Pinterest a few tutorials on how to stencil a wall before I started. My favourites were Sarah's from While They Snooze (which is where I also got my template from), Kathryn's from Nanny Goat, and Kate's from Centsational Girl. I thought I had everything all figured out, then my sister came over and told me my ideas would not work. Turns out she was right...sometimes my ideas need vetting before they come to fruition, haha
I printed my template and glued it onto some cardboard to make it stiffer. Realize that the bigger you make your shape, the less work it is! Most tutorials advise printing your shape on multiple pages and making it quite large. Honestly, I couldn't figure out how to print the shape larger with my computer so I left it the standard size. I think since I didn't do a complete wall, the smaller size worked, but for a complete floor to ceiling stencil I would go larger.
I taped a level to the stencil to ensure that each time I repositioned it, it would remain level. That helped tremendously. Then it was just a matter of tracing the stencil over and over onto the wall. A lot of this project was done by "eye balling it". I traced the first pattern, moved it a bit to leave a gap then traced again, moved it to leave a similar gap and traced again, etc.
To do the corners, I printed another copy of the stencil but didn't glue it to cardboard. The bendy-ness of the paper allowed it to be folded and traced in the tight spaces.
Once everything was traced it was just a matter of painting between the lines. I had a few disagreements with my sister on what colour to paint. I originally was going for a non-dramatic shimmery taupe. My lovely sister called the colour opalescent urine... So we tried white. It was okay, but we were running into the issue that we had traced with a pencil. FYI - light coloured paint doesn't cover pencil. I recommend if you want to do a light colour stencil then trace with something that is similar in colour or be prepared to do multiple multiple coats. So we tried black and it looked really good and it covered the pencil. It was more "in your face" than I was going for originally, but I love it now! Here is our testing phase (don't worry, the test spots got covered by the chair rail!) and partway through the painting process.
If you were to get up close and really study it, you would see that the gaps aren't all quite perfect and the lines aren't all quite uniform, but from far away, the effect is that everything is the same. (And really the only people that notice the imperfections are your own family members anyway who get super up close and stare at it!)
In total, it didn't really cost anything. I used black paint that was already on hand, and printed the stencil myself. It only cost time and manual labour! My sister helped a lot. She spent one Friday night and a whole Saturday working on it while I was away at work. Then I plugged away on it for the rest of the week when I wasn't at work. So about 5 days and quite a few hours...but the end result was totally worth it! Even when you just pick away at it, you will finish!
I love it and keep making trips to my entry just to look at it! It makes the entry so much "homier"!