I'm going to assume that since you're sewing jeans, you've probably traced and cut out a pattern or two in your lifetime. I'd still like to give you a few tips that maybe you haven't used before.
But before we get into tracing and cutting, let's take a brief moment to talk about selecting your size.
Choosing a Size
This seems to be one of the scariest parts of making jeans (or any pants, for that matter) for a lot of sewists. It isn't as scary as you think though, especially with pants made from stretch fabric. I recommend that you choose your size based on a snug hip measurement taken at the very widest point of your bottom. Move the measuring tape up and down until you get the highest measurement, and go with that.
If you are anything like I am and have had a kid or two (or three or six), your waist measurement might be proportionally bigger than your hips. No sweat. These jeans have stretch built into the waistband and will work just fine even if your waist is an inch or two above what is stated for your hip-based size.
In other words, if your hips are 43" (size 33), but your waist is 35" (size 35), you can probably get away with a size 33". If you have more than 2" difference, I do recommend grading in-between sizes. I also recommend cutting the waistband a little longer than the pattern piece if you are in any doubt since it can easily be trimmed down to size if needed.
In my case, I have made these jeans in both size 26 and 27. My hips are 36", and my waist varies from about 27-29". Both pairs fit great thanks to the stretchiness of the fabric and the negative ease at the hips.
On the other hand, if it's your hips that are proportionally bigger, you might want to grade out at the hips to a larger size. I recommend you consult others in the Baste + Gather Sewing Chat group to get their experiences and make a decision.
One other thing to remember is that these jeans have a 5/8" seam allowance. That gives you plenty of room to let them out a little (or take them in) when you get to the point of basting together the outseams.
Seriously - don't sweat this part too much. You'll be surprised at how much you can ad lib your way through making these jeans. They are quite forgiving and can be modified as you go. You'll also be shocked at what a difference in fit you'll get from different fabrics. I have a size 26 pair that fits more loosely than a size 27 pair and a different size 27 pair that's looser than both the others. They are all different denims with slightly different stretch amounts and fabric content/weight. The key is to simply try them on as you go, making adjustments as needed.
Tracing & Cutting
First, print and assemble your pattern as guided in the pattern instructions. Note that both the print-at-home AND copy shop versions are layered, so I recommend printing only the size(s) you need since the lines overlap in several places.
Once you've got your paper pattern ready, I *highly* recommend tracing your pattern onto Swedish tracing paper for several reasons.
Swedish tracing paper is different from regular tracing paper in that it performs and feels little more like fabric. It is completely transparent (so you can see the pattern lines), but it won't rip or become distorted. You can also iron it just like fabric if you have to fold it up into an envelope and re-use.
Printer paper and regular tracing paper tend to tear, come apart and get tattered after a while. They're not the easiest to iron, either. Just trust me and get some Swedish tracing paper. You'll thank me later.
I also like to use large washers from the hardware store instead of pins to hold down my tracing paper (and to hold down the pattern when I am actually cutting the fabric). My husband picked these up for me at Home Depot for a few bucks. I like to have about 20-25 on-hand at all times.
I keep a yardstick around as a straight-edge when I have a long, straight line to trace. A large quilting ruler also does the trick (and I'll be using one later in this post).
But here's a little trick - you can also line up straight-edged pattern pieces with the straight edges of your tracing paper to save the time and effort of having to draw that line (see above). Another thing you can do is to abut pattern pieces with straight edges against each other. Then, you only have to draw/cut that line once.
When tracing your pattern pieces, be sure to label them with pattern name, pattern piece, size and cutting instructions. Also be sure to accurately transfer the grainline and any notches/pattern markings. You can see in the photo below that I've actually drawn my fly template on the leg front piece. It doesn't really matter where you put this - it's just a guide for tracing.
With flared jeans, it's especially important to make length adjustments before cutting your fabric. If you wait to hem them at the end, and you have to take off several inches, you will lose a bit of that gorgeous flare. It's almost as important with the Kendalls since the lower leg is contoured for a flattering fit.
My suggestion is to do one of two things: 1) measure the inseam of a pair of similar existing jeans to determine how much to adjust the inseam or 2) measure your body from the crotch down to the floor while wearing your intended shoes. Keeping in mind that the Birkin Flares have a 34" inseam as drafted (Kendalls are 30"), make adjustments at the two length modification lines.
For example, if your desired finished inseam on the Birkins is 32", you will take out 1" at the top line and 1" at the bottom line for a total of 2" removed. You can add length the same way by cutting the pattern apart at the lengthen/shorten lines and separating them the desired amount.
If you have proportionally short/long calves or thighs, you may choose to add or subtract all your length at just one of the lines.
A couple things to keep in mind... My jeans are drafted for the legs of the average 5'6" woman. If you are an average 5'4" woman, that does NOT translate into a 2" inseam difference. Remember, your legs are only about half of your height. So, that would probably be more of a 1" inseam reduction needed. Also, the Birkins are drafted to be worn with high heels/wedges/platforms. Depending on the type of shoes you normally wear, you might also need to make adjustments.
If you simply want to deepen the hem (or deepen it in addition to lengthening/shortening the overall inseam length), follow the instructions in the pattern. This is shown in the image above. You simply extend the hem the desired amount (the drafted hem is 1" total - so 1/2" folded up twice), angling it in very slightly to mirror the angle of the flare (so it tucks in there nicely when folded up and stitched).
Next, be sure to line up your pattern's grainline with the grainline of your fabric.
Now, I know what you're thinking..."Aha! This is important because it prevents twisting of the legs!"
Well, yes...and no. It IS super important for this reason, but being off-grain isn't the only thing that can cause twisted leg syndrome. I have researched this topic at length, and I don't intend to re-hash it all here in this post. Suffice it to say that twisted legs can be caused by the weave of the fabric, being off-grain, whether the pieces are cut individually or in pairs and several other factors. You can research this on your own to try to work it out, or you can look at everyone else wearing their twisted ready-to-wear jeans and not worry about it. Do your best, but don't obsess over it. (That's my philosophy, anyway.)
You can see in the photos above and below that I like to use a quilting ruler to line up the grainline with the selvages.
After you've cut your front pieces, be sure to trim away the fly extension as directed on the pattern. In case you forgot to trace the cutting line, simply cut 5/8" off as shown below. MAKE SURE YOU ONLY CUT THE WEARER'S LEFT PIECE!
Also be sure to mark the little diamond on the fly. In the image below, I've marked on the right side of the fabric, but it would actually make more sense to put this on the wrong side since that's the side you'll be looking at when you sew. No biggie though; you can simply put a different colored pin in that spot to remind you to stop there when sewing the front crotch.
Finally, I trace off all the pocket markings using Saral Transfer paper. I have tried numerous different kinds of transfer papers, but this one is hands-down the best!! It shows up well when you need it and washes off/brushes off easily when you don't. It also comes in several great colors (get them all in the sampler pack) for use on different colors.
I use a smooth tracing wheel (no notches) to trace the markings. Doesn't it look great?
All cut out and ready-to-sew!
In the next session, we're going to start sewing. Get ready to have a ton of fun and make some awesome jeans!