Reddit mentions of Patternmaking for Menswear

I just started down this path myself. Luckily my mom has a sewing machine and some basic knowledge of how to use it, so that's been really helpful. It's an old-school fully mechanical Bernina, not sold any more but it looks to be similar to the 1008 model. Really nice machine, fast, quiet, has a ton of built-in stitches, a button-hole-maker, and easily interchangeable presser feet, but it's also way more expensive than I would spend if I had to buy my own. Unfortunately I don't have any recommendations for entry-level machines. But certainly it's worth it to do some research on what it needs to be capable of doing. For example,

• if you want to sew denim, or canvas, or anything with leather, you're going to need a beefy heavy-duty machine that can punch threw at least a few layers of thick fabric at low rpms.
  
• the two basic stitches are a straight stitch and a zig-zag. You want adjustable stitch-length, and adjustable zig-zag-width. With those two, you can do just about everything. But there are also fancier stitches that make it easier/more-professional-looking to, for example, overlap the raw edges of fabric (helpful when sewing knits, see the inside of a t-shirt or sweatshirt), or to join two pieces together fully encasing the seam allowance (check out some of the seams on a fleece).
  
• fancy presser feet: make sure you can get a zipper foot if you want to sew anything with zippers, an edge-stitching foot makes it really easy to sew a straight line really close to the edge, a button-hole foot is needed for sewing button holes (forget doing that shit by hand), and they also make feet that can automatically do a rolled-hem (see the bottom edge of your dress shirts). there are probably others too.
  
  

  basic equipment:
  

  
  

• get a rotary cutter and a rotary cutting mat. 24" x 36" minimum. Ideally it has a grid on it. And you also probably want to get a clear ruler, 24" x 6", which should also have a measuring grid on it. technically you can do with just scissors, but, it's a PITA
  
• pins. lots of pins. the good kind have a glass ball on one end, ideally colored so you can find them easily in your fabric. pins come in different sizes, silk-size (really skinny) is good for most fabrics, but you want something beefier for the thicker fabrics otherwise you'll bend the skinny ones. also, don't sew over pins. take them out just before they get to the presser foot. on that note, get (or make) a pin cushion.
  
• depending on what you're sewing, you'll need an ironing board and an iron. ideally one that doesn't auto-shut-off. also ideally the ironing board is a rectangle, but you can get away with the standard shaped ones too
  
• sewing machine needles. make sure they fit your machine; there are different styles, altho most home sewing machines take the same kind. size 12 or 14 is pretty fine, good for knits and dress-shirt-weight wovens, but you want size 16 or 18 for heavier fabrics. get a bunch (5-10 of each size); you will break them. they also dull out with use. usually you want ball-point, so it won't pierce the threads of the fabric, but sometimes you need the sharp kind meant to cut into the threads. your pattern should suggest which kind and size to use.
  
• a thread-ripper, a good pair of scissors (super sharp, only used for cutting fabric, and shaped so the bottom edge doesn't move when you snip), a little ruler with an adjustable edge guide for measuring folds, tons of thread (way more than you think you need. I would guess it took about 200 yards to do a single size-medium fleece, altho granted, there are a lot more zig zag stitches when you're sewing stretchy fabric)
  
• if you want to get into tailoring, there's a bunch more specialized stuff, but that should be enough to get started
  
  

  patterns:
  

  I was lucky and happened to want to get started at the same time as McCall's was having a huge sale, so I was able to get a bunch for $3 each. But usually they're more expensive. Do some research; there are good patterns, and shit patterns. Also, the instructions that come with patterns are universally crap. And by that I mean they're optimized for a combination of the lowest-common-denominator of sewing skills, and a minimal amount of print-space. Definitely read them front-to-back before you begin, but also supplement the included instructions with an ample dose of youtube videos.
  
  I tried starting with a dress shirt; that was a mistake. Very difficult. (It didn't help that the pattern I got for it fell into the shit category, and I ended up needing to make a ton of modifications. McCall's M6044. Do not recommend.). I'm currently in the middle of my third muslin and it's starting to come out okay, but I still don't feel comfortable giving it a go with the good fabric. Fleece is very easy to work with; I just finished one that come out actually pretty decent, using the Kwik Sew K4032 pattern. It's got some challenging parts, especially the directions for the zipper pockets weren't very good, but on the whole way more simple than a dress shirt.
  
  

  supplies:
  

  I had a really tough time finding good sources of by-the-yard fabric online. I ended up ordering from califabrics.com. I'm happy with everything I got, but it's kind of a crap-shoot if you don't order samples first. Would recommend sourcing fabric locally, if you can, or at least order samples before you commit to a bunch of yards.
  I got my zippers from sailrite.com. As you can guess from the name, they're very focused on nautical stuff, but they have a good assortment of YKK zippers that are way less expensive than anywhere else I could find. Good youtube instructional videos too.
  Otherwise, I got some stuff from Joann's (check online first, sometimes they have online-only sales but let you pick up in-store), and random sellers on amazon (muslin was cheapest there, but the stuff at Joann's was much nicer, almost good enough to actually wear if you wanted to).
  
  

  resources i've found helpful:
  

• Patternmaking for Menswear - can be found on libgen
  
• https://malepatternboldness.blogspot.com/ - especially the sew-along links in the sidebar
  
• https://off-the-cuff-style.blogspot.com/ - some good stuff on dress shirts
  
• Shirtmaking - the "bible" of sewing dress shirts
  

I think it's because sewing is predominantly female hobby, so pattern companies ignore menswear...
Burda magazine has some patterns
http://www.burdastyle.com/pattern_store/patterns?for=2&page=1
https://beta.burdastyle.de/shop/schnittmuster/herren

You can also try to learn pattern drafting with these books

https://www.amazon.com/Pattern-Cutting-Menswear-Winifred-Aldrich/dp/1405182938

https://www.amazon.com/Patternmaking-Menswear-Gareth-Kershaw/dp/1780670168

https://www.amazon.com/Patternmaking-Menswear-Contemporary-Myoungok-Kim/dp/160901944X

I did what u/Pancake_nips said (except I just took measurements and did some tracing instead of disassembling the garment) and it worked out pretty well. Here's a very useful sew-along.

It takes a lot more work, but you can make your own pattern from scratch. This book gives you directions on making a sloper, and then has instructions for several patterns based off of that, including jeans (and tops and outerwear too).

Looks like maybe bleached e:denim canvas which you can then distress and dirty. You can then preserve that and get the "hard" layer by waxing it.

This and this are good books for patternmaking. The second offers halfscale patterns that you can blow up and modify if you have access to a plotter.

Construction is going to be pretty difficult to learn, especially manipulating denim with a home sewing machine. You'll want to learn how to do a flat felled seam if you're working with denim. Unfortunately, the roping will be hard to achieve without a chain stitch machine.

You know AI, so this is really just about how to draft patterns.
There's a number of books on the subject, but for you (based on your post looking for men's sewing patterns) I would recommend
Patternmaking for Menswear by Gareth Kershaw: https://www.amazon.com/Patternmaking-Menswear-Gareth-Kershaw/dp/1780670168

This will read as a shameless plug, but the patterns on makemypattern.com can be downloaded as an SVG that you can open in AI. This obviously does not teach you to draft them, but it does allow you to tweak them.

It is tougher starting out as a guy I think. Don't dismiss those outdated patterns. They are good for practice. A shirt is still a shirt even if its a little odd. But if you can afford it I have this one

https://www.amazon.com/Patternmaking-Menswear-Gareth-Kershaw/dp/1780670168

Well worth it for what I learned from it.