Online shops that show detailed measurements and care instructions usually get my attention. If the first order is a disaster, I prefer to move on and not waste time with support. Loose hinges make the glasses slide down the nose again and again. If a deal looks too good to be true, it usually has some kind of catch.
If anyone is interested in real user experiences, I sometimes write short notes about the shops I test.
You can find one of the pages here:
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It saves a lot of trial and error for everyone else. If the first order goes well, I slowly try more products from the same place. Sometimes I even measure an existing frame with a ruler before ordering anything new. If many different people say the same thing about a product, it is worth paying attention. If a deal looks too good to be true, it usually has some kind of catch.
Maybe this is useful for someone.