Ethical Lingerie Shopping - A Beginner's Guide
1/ Find your own definition of "ethical"Without getting into too much philosophy, "ethical" is quite a contested term. While I tend to consider ethical everything that is not made in a sweatshop nor has a 'problematic' marketing, your definition can be more demanding and include environmental concerns, for instance.
2/ Know your best-fitting size and your measurementsMany ethical lingerie brands make their items to your own measurements, so your first step might be to buy a measuring tape. Bra-fitting is about as contentious as the definition of ethics but a good place to start is A Bra That Fits. If you want to get fitted professionally, just know that independent stores are a bit of a hit and miss, especially in France. In UK, Bravissimo is usually a safe bet while in the US, Nordstrom is not too bad. Also, do not forget to check brands' individual size charts as they can vary quite widely, especially for bralettes.
3/ Have realistic expectationsEthical lingerie is the opposite of fast-fashion, so you might have to wait quite a bit before receiving your order and the prices are usually higher, especially for underwired bras, which are the most complex item of clothing to design and produce. Designers will usually offer small reductions for some special occasions but don't be the person who complains about their pricing and asks for over 50% off. Similarly, bigger cup sizes are expensive to develop and not all brands can afford to introduce them, so there is no need to pressure them into it, a polite e-mail asking them if they have plans for size expansion will get the message across perfectly.
4/ Budget, budget, budgetEthical lingerie has a cost, so my advice would be to plan your purchases in advance. New releases are not as frequent as with fast fashion so long-term thinking is easier. Personally, I go with buying plans I update every 6 months and I even draw little lookbooks to encourage myself to stick to them and not be lured by sales from bigger, unethical brands.
If you really cannot afford ethical lingerie, do not feel guilty, our economic system relies on exploitation so you are not at fault. You can venture into thrifting in person or on apps such as Depop or Vinted or into buying older stock on Ebay or secret sales websites (I am preparing an article on the subject).