If I’m going out during the day, as in when there’s ANY significant sunlight, I’ll wear sunscreen under my foundation. This includes if I go out at like 6:00 pm and the sun sets at 7:00 pm haha. Yes, I know I’m crazy. For reference, I wear a mineral-sunscreen mixed with a bit of mattifying primer with SPF. I wait for that to dry, which takes about 10 minutes, before moving on to foundation.
Then, I always apply foundation with a Sigma F80 or F84; basically a flat or angled kabuki brush. And I lightly stipple on my foundation. I never, EVER buff because that’ll risk moving or even removing the sunscreen underneath. I know that takes a bit longer to blend, but if that keeps my sunscreen intact, I’m willing to do it.
Just as a side note, because of the way I apply foundation, I tend to use true liquid foundations that don’t set too quickly. Therefore, things like the YSL Teint Resist, which sets very quickly (and gives a slightly chalky initial finish) are off the list. Furthermore, I know that I’ve raved about the Laura Mercier Silk Creme foundation before, and while I still like it, I don’t reach for it anymore because that product requires too much work. Because it’s quite thick, I have to rub it around a lot, which will ruin my sunscreen.
I’ll probably just list all the foundations I’ve tried and all my notes on them in the future, just to give you guys a foundation guideline/map. Maybe I’ll do corresponding YT videos… Let me know if you guys want to see that.