The process outlined in the book is good - I'd recommend it (I've since purchased the book). I started this project in November, so I honestly don't remember a lot of the details. The only thing I do remember is that it is really important to start with the grainline and get that spot on. I didn't do that initially and I had pant legs that twisted around like a barber pole. It's a difficult part to just eyeball.
The front of the first muslin was good, but the back was a disaster. I made some adjustments and cut new back pieces. After I had the main pieces how I wanted them, I made a second muslin to test out all the small pieces that I was drafting based on measurements rather than tracing the original (waistband extension, fly guard, pocket flaps, etc). It was also helpful to practice techniques like making the welt pockets. After 2.5 muslins I was confident enough to cut into the good stuff.
All things considered, I'm really happy with how they turned out. I used a heavy white denim with a tiny bit of stretch and I think something with a little more drape (or any drape at all) would have been better. Are these pants a perfect fit? Nope. Are they a satisfactory fit for me? You bet. Scrutinizing every wrinkle, bump, pull, or bubble sucks a lot of the joy out of sewing for me. I like a good fit, but being obsessive about it is stressful. Probably because fitting isn't my strongest skill.
Front view (with sitting wrinkles):
I like the shape of the front pocket opening - partly straight, partly curved. It lays smooth along my hip, but is easy to get my hands into.
To avoid bulk at the end of the waistband, I extended it so that it folds back and attaches to the waistband facing. This way there is a fold at the end rather than a seam. Also, these hook-and-eye closures that get poked through the fabric and have a supporting plate on the backside are soooo much nicer than the kind that you stitch on. They feel more secure and allow for a smoother, flatter waistband finish. This is the first time I've used them and clearly I need some practice getting them on straight!
And there will be more pants made from this pattern. It was a long process, but I think it was less cumbersome than starting with a pattern and trying to make it what I want.