A. That gorgeous dress that started in your price range ($29.99) on eBay has gone up to $187 with another six hours left, and you sadly delete it from your watch list and throw a shirt on the special hanger you had set aside for it in your closet.
B. Something perfect (and cheap) catches your eye, but the seller's claim that it "feels like silk!" alerts you that you're dealing with an amateur and, probably, a nylon piece from the 60s that will make you sweat in all the wrong ways. You sigh and move on.
C. She wants $995 for that Lilli Ann suit? Someone might pay that. But not you.
D. It's perfect! But it's 8" too small in the waist.
What can you do? Say goodbye forever to those perfect pieces, poached from your loving hands by eBayers with deeper pockets, or impossibly wrongly sized for your figure? If you have a few tools, good sewing skills, and the tenacity to devote a few dozen hours of your time, never fear - you can have that dress. And you can have it in your size, in real cotton (silk, linen, wool), in the color that flatters you, without any missing buttons, moth holes, mysterious stains, or "almost unnoticeable" repairs.
I originally intended this instructable to cover a variety of different pattern styles, but finally admitted it would take me at least another two years to finish it if I went that route (since I'm currently far away from my beloved machine, will be so until August, and generally only undertake this kind of thing during the summer). So I'll be covering the design that I made, pictured on me, and if you have questions about different details, post them in comments and I will answer them to the best of my ability.
You will need:
1. Intermediate sewing skills commensurate with your chosen design
2. A body block (directions in The Costume Technician's Handbook), or a plain, very fitted button-down style shirt with no ruching, gathering, elastic, or frim-fram on it, that you are willing to sacrifice on the altar of Style (generally available at thrift stores)
2. Kraft paper and some basic drafting tools - at least a measuring tape and pens, preferably also a long straightedge and a couple of hip curves (available online or at large fabric stores, not very costly)
3. Adequate photos of the design you want to reproduce (see "adequate photos" for more information)
4. Enough fabric for the job (see "fabric selection" for more information) and thread / notions etc.
1. Building your own dress is rarely cheap. You are unlikely to spend less than $60 on this project, depending on how much fabric you need and what the fabric costs, and what else you need to complete your design. But it's still cheaper than that outrageous Lilli Ann.
2. This is also not one of those "make a prom dress out of a paper bag with no sewing in under 45 seconds" kinds of deals. Expect to invest at least a week.
3. Choose a design that suits your sewing level.
Step 1: Adequate Photos
Seam lines (most important) - vertical seams, darts, waist seam
Zipper / placket placement
Collar shapes & lapels
Pockets - are they hidden in seams, or cut and then piped, or applied as patches?
Note: none of the images in this step belong to me (except the one of the black dress). I haven't shown the kind of photo I most usually use for inspiration -- photos of dresses I see on eBay or Etsy -- because I don't want to step on sellers' toes. But I'm still going to provide a few tips on how to use them.
The striped dress on the model is a great working photo, because it's very easy to see on striped fabric how the seams are shaped. For example, you can tell by looking at the presence or absence of deformations in the stripe that the bodice has bust darts but not waist darts. You can tell from the hem of the skirt that the dress does actually open in front (sometimes front buttons are just decorative), although the midriff section definitely does not open in front -- so it's either a separate belt that fastens in the back, or the dress also has a back or side zipper. The stripes also tell us that skirt waist seam is pleated, which is where it gets all its fullness, because no side seams are visible and there is no deformation of the stripe, which suggests the skirt is one continuous piece of yardage, or at most two.
The photo of the linen dress with bolero is one I hoped to use to make a bolero to match my linen dress, but I didn't get around to it. Sigh. Anyhow, you can see that the design is super simple: the collar isn't even a separate piece, it's just cut as part of the bodice, which is lined/faced, and the lining/facing becomes a contrast element. Darts are replaced by gathering at the high waist, the bow hides the single-point closure (probably a hook and eye), and the sleeves look to be set-in, so cut separately.
As for the black dress, it's not a great photo to work from because the dark color obscures some details, but you can still tell it has a shawl collar, three buttons to close the bodice, waist darts (also bust darts, but it's hard to tell), and set-in sleeves with cuffs. You can assume the skirt is a full circle because it has no pleats at the waist but the hem is very full.
The illustrations all show various useful details: I particularly love the advertisement for "Linen-Look Rayon" because they've actually drawn the weave on the fabric, which shows you just how the four-piece skirt is laid out on the fabric! Also, you can see the same kind of sleeve detail that I use for the linen dress in this instructable. The line sketch also shows that there are two waist darts in the back. No darts are drawn in the front, but I will assume they are there, because the dress is very fitted. I mean, her waist is as small as her neck, there have to be darts in there.
The playsuit / sundress sketch shows a design I love, with the skirt buttoning on the side to the waist (there's probably a zipper from the waist to the armscye, or else a back zipper). Instead of shaping the bodice with darts, the dress has a front yoke that also forms a collar, and the bodice is pleated underneath. There are no waist darts. The skirt looks to be made of six panels.
The "advance" pattern shows a very simple dress with no waist seam. I would put one in if I were making this dress, because it's way more economical in terms of fabric use, and I like to belt my dresses anyway, but something cut like this would be very sleek. The dress is probably cut in eight pieces, maybe six: you can see two front centers and two front sides, and the front sides also have an additional dart that crosses the waist. A sketch of the back would enlighten us about the other side, but it's less important; if you want to preserve the same fullness in the skirt, you'll cut four pieces for the back as well. The blue dress appears to be cut in just four pieces, with the sleeves cut as part of the bodice. I like the cute notch detailing on the pink one's neckline: with a facing, you can make the edge any shape you like, pretty much.