For some cases it's more obvious (e.g. dry skin tends to be flaky, oily might be, uh, shinier?), but when it's not to the extremes but also maybe not a mix, what's a decent rule of thumb to narrow it down?
Similar regarding sensitivity. A lot of skincare products market towards these conditions with the expectation that you'll know somehow, but it's not always so obvious, and a doctor's visit isn't always affordable (which is probably the best answer here, tbh, but let's suppose it's not a severe skin condition one's trying to identify).
Personally, I look more at the ingredients of the products than for which skin type they market to. Mainly because I have sensitive skin and I have learned the hard way that leaving out scent and perfume from the ingredients doesn’t necessarily make my skin like it. My skin can also be dehydrated, but very oily at times was also confusing. So for me hydration is key to tackle most of my issues. What helped me was a lot of trial and error. But to save time and money, I would definitely recommend the book “Let’s face it” by Rio Viera-Newton. It helped me understand the different basic ingredients and skin needs and how to recognise and tackle them.
Agreed! I would say "skin types" is a made up term to make marketing products easier. In reality it's much more complicated than that.
(And thanks for the book tip, now I got something new to read 😍)