Don't know how to match your foundation to your face? Accidentally bought the wrong shade? YouTuber Tina Yong has a tip: pick three foundations and draw a line on the side of your jaw to see which blends into your skin and matches your neck perfectly. If you bought a foundation shade that is too pink, she explains that you can actually use it to cover dark under-eye circles or any areas that have pigmentation. If you bought something too yellow, you can use it to cover up any pimples or redness on your face."