(For a reader who wants to suss this)
Friday: Reddish skirt, black top, silver jewellery to brighten it, shawl.
Saturday (day): trousers (also streetwear), reddish top. Wash or steam top on return to hotel. Shawl.
Saturday (night): Black dress. Red jewellery. Shawl.
Sunday (day): Skirt again, this time with the other top. Shawl.
Shoes: only one pair is necessary for this set of outfits. But eventually, I put in another, extra-low, second-hand pair because I know some of the floors are very hard. I don't want to be dancing less than I wish because my feet hurt.
Emergency Chocolate for eating at 02:30.
Foldable shopping bag to do duty as milonga bag and street bag.
Underwear for all the above
Silk nightwear(packs to nothing).
Makeup, toothbrush, comb. Hair thingies. Contact lenses.
Thingie for plugging ipod into other thing, in case that's possible in the hotel [it wasn't], so I can do some exercise.
Camera, fully charged.
Streetwear and warmth:
Travel in jeans, t-shirt, cardigan, and shawl worn as scarf, coat, street shoes.
Street-to-dance trousers are already in.
2 pairs minisocks.
2 Clean t-shirts.
Swimsuit. (Everything else will be hired).
Logistics (in top or outer pocket of bag):
Airport Security bag with shampoo, conditioner, toothpaste, Savlon, deodorant, mascara
Purse of UK currency + debit card. Purse of Euros.
Fully charged mobile (it's only a weekend, it's not a smartphone, I don't need the charger).
Boarding card from online check-in.
Schedule and orientation sheet.
Notebook and pen.
My basic formula:
Devise an overall colour scheme for the whole weekend; for example blue/green/silver, or black/crimson/beige, or blue/purple/black/silver. Imagine you're thinking up the heroine's dresses in a really cheap romantic novel - you probably know the way they do it.
This colour scheme should result in a maximum of two pairs of shoes. If more are taken, it should be for other reasons of necessity like floor conditions and hours of dancing or your personal tendency to get blisters or the possibility of breakage.
One formal skirt or pair of trousers.
Two different tops that both go with the above, at least one of which should be washable and quick-drying, and at least one of which should be suitable for a daytime milonga as well as evening.
One formal one-piece.
One less formal skirt or pair of trousers for day milongas, that should double as streetwear and also go with at least one of the tops, preferably both.
If it's the kind of festival where there are more than four milongas in total (say, up to seven over a long weekend - F1 F2 Sa1 Sa2 Su1 Su2 M), then it makes sense to add another another skirt or pair of trousers some more tops. I may make space by leaving out the one-piece so that I have more outfits for the same amount of clothes, at least if some of it is washable. Then I try to make sure that everything, or almost everything, will go with at least two other things and produce a satisfactory outfit.
If you prefer to wear dresses rather than tops-and-bottoms, then that's a different situation. As long as they are not too bulky, you just take enough, and the only problem is whether they go with your shoes.
I think it's pretty easy for a woman to do a European-style 'encuentro' and comfortably fit inside the Ryanair hand luggage allowance. You just need a well-tried working wardrobe and confidence in your own style. It's not a good idea to vary your look much; if you take one dress in a totally different style, shape or colour scheme, all it does is confuse people about which person is you, waste time and cause you to miss dances. I've made this mistake a couple of times.
If I was staying in a hostel rather than a hotel, I might need to take my own towel, which would mean a slightly bigger bag. In winter, I use the bigger bag and I take thin layers.
But maybe the important part of my packing technique is a truculent, selection-committee attitude to my wardrobe. I try to get out of the frame of mind in which I want to take all sorts of things that I like, and get into one in which every piece has to justify its place by teamwork in pursuit of a plan.