Cutting part 1
There are so many photos that posting about cutting will take several posts. I'm going to start by posting about cutting out my upper fronts and back, which I did this morning.
First, I want to address symmetrical versus asymmetrical plaids. Fleetwood was symmetrical and Tanglewood is not, so there are not as many matching opportunities with this shirt. I'll explain as I go along where trying to match with an asymmetrical plaid is futile. This is a bit hard for me to explain, but I'll try! To give an idea what I mean, this is Tanglewood:

It's not PERFECTLY symmetrical as some colors very in the lines on either side of the main motif, but the geometry of it is symmetrical. I could fold the fabric in half and the pattern would flow across the cut. (I should have taken a photo demonstrating but didn't think of it).
In contrast, this is Fleetwood:

There is no way to fold Fleetwood and keep the pattern uninterrupted across the cut edge. With tanglewood, it would be hard to see the cutline because the pattern would flow across. Please tell me if this makes no sense and I'll try a better explanation.
Ok, on to cutting:
Disclaimer: most of this information, I came up with on my own. My mom helped me cut out a plaid skirt when I was in high school and beyond that, my learning has been mostly trial and error with some books and internet knowledge thrown in. I'm sure there are other ways to do this, and I'm absolutely open to input!
First, I take a good look at my fabric and decide where I want the center front. I don't want a bold red line running up the middle, so I chose a subtle line between a yellow and blue line. My scissors point to this vertical line.

Next, I place the front pattern piece on my fabric and pin the marked center front line on top of my chosen center front vertical line on the plaid. I only do one side at a time, never a folded fabric layout with a plaid.

Smooth out the rest of the pattern piece, pin in place, and cut.

Then, get your "helper" to threaten to cut your beautiful new fabric (optional).

Next, I unpin the pattern piece, flip it over, pin and cut the second side. Make sure to match up the center front vertical line again, and match everything up vertically. Because of the unsymmetrical plaid, the side seamline and shoulder seamline will not match between the two fronts.

Next, I fold under one facing and put it on top of the other front piece, admiring how well my plaid flows across the front.

There was no way to make both sides seams match up horizontally because of the large scale repeat, so to keep my sanity, I chose the same center line for the back. Without folding the fabric, I lined up the center line on my chosen area of plaid, making sure that vertically, fronts would match to back, and I cut out one side. DO NOT CUT THE CENTER BACK LINE!


Unpin the pattern piece, flip it over, line up the center line again, pin and cut, again making sure that vertically the two sides match but not worrying about the horizontal plaid repeat.

Ok, deep breaths. We're done for now. Has this made sense? Please ask if you have questions, and I'll try to answer. Later today, I'll put up info on cutting the lower front pieces and collar.