Right now I am suffering from Regency fever. I am so excited about the upcoming ball, and I can't stop looking at dresses and period sources. I've also realized that not everyone has the resources to get a nice reproduction dress ready at the drop of a hat. Now, lucky for those people the Commonwealth Vintage Dancers rarely require period costume for attendance to their balls. So pop on some formal outfit you have lying around and come join the dancing! Don't let the lack of the perfect costume intimidate you out of showing up - I'd be so much happier to see a lot of people having fun and learning than a few people perfectly dressed.
On the other hand, it always feels more special to be able to dress up and feel like a princess. And in a particularly nice twist of fate, the Regency silhouette is not that difficult to achieve. Once you have the silhouette right, you will have captured the feeling of a Regency outfit, even if the specifics are off. So here is a guide to faking a Regency outfit, stressing the most important elements for getting the right silhouette.
The High Waist
The most noticeable feature of Regency dresses is their artificially high waistlines (often referred to as an empire waist). If you can get this right, you have made the first step towards a good Regency silhouette. Luckily, this is not a dead fashion. I know that empire waists have been popular within the past few years, which means ideal opportunities to find something appropriate in the used clothing stores, or in your very own closet. Go look!
If you have a dress without a defined waist (don't try this if there is a defined waist lower down, though), you can add this definition by tying a plain ribbon around your ribcage. This is a very period look, and is especially spiffy if you add tassels to the ends of your ribbon. Ooh!
The Long Skirt
There is no way to avoid this. If you have an absolutely perfect Regency dress that ends at the knees, you are going to look silly. Well, actually, you will look really cute - but you will not look Regency. On the bright side, this too can be fixed! There were points in time where the "tunic" look was very fashionable indeed, so you can put together a stunning early Regency ensemble by layering your too-short high-waisted dress over a long skirt in a matching or coordinating color. If you have a really good color match (like white and white), or a nice sash to make the change less jarring, you might even layer the long skirt over the too-short dress and make it look like one long dress.
A lot of formal evening dresses in the period had trains. That is lovely, but you are unlikely to find them on modern garments. In fact, you should just count this as a blessing, as you won't have to figure out how to dance in a train (hint - it involves pinning up, removing, or otherwise securing it... too much work). So you should know they exist, but instead of worrying about replicating them, you should come dancing with me!
Sleeves of Some Description
So at this point you have a high-waisted dress with a long skirt. Unfortunately, a lot of modern dresses that will get you to this point are strapless. I am going to strongly urge you to do something about this. I have trouble thinking of anything less 19th century than a strapless dress. But never fear! There are a number of things you can do about this. If you are particularly crafty, you can always add sleeves, or at least straps. Jumpers are legitimate for Regency, though they get worn over a blouse. Short sleeves, which might be quite puffy or rather plain, are what I most commonly see, but long sleeves are also alright. No sleeves would be unacceptable, though.The good news if you are not crafty is that little jackets called "spencers" were all the rage in the Regency. I have frequently seen extra-short-waisted jackets in modern stores that would serve this purpose well. You could also wear a short bolero jacket, another style I see all the time. You might even get away with a shawl or similar covering, but if you are relying on it to cover otherwise bare shoulders for an entire evening, you are probably better off with the jacket. If you have no luck locating a short jacket, go for a long robe instead, and tie a ribbon around your ribcage and over the robe. This should provide you with sleeves, a high waist, and a tunic-style dress all at once.
An Appropriate Neckline
I add this because it matters, but there is not much you can easily do to modify this if it is wrong, so try not to worry as much about it. It is certainly a much less important structural element for building the Regency feeling than the previous three things. The good news is that the neckline styles varied over the Regency period, so you can get away with more than you might have expected. The most common style I see is the scooped neck. It is usually somewhat low-cut, and can be very low-cut, and had a nice round shape. There were also a lot of dresses with very wide square necklines. I don't even think of these as "square" necklines so much as "straight," since they look like they stretch flat across from sleeve to sleeve. Hopefully the images will help where my descriptions are failing. There were also v-necked dresses, with plunging necklines.