Some people recommend applying concealer after foundation while others say you should put it on before. I prefer to put it on first so that the foundation can even out any differences
in color. You can always touch up with a little extra concealer afterward.
To apply your concealer, all you really need are your fingers. You may also use a concealer brush, which can by useful in getting at little crevices, like around your nose. If
you do use a concealer brush, make sure it is very clean or it will deposit bacteria right
where you need it least, back on your acne. This will only make your acne worse. Clean
the brush every day with a little mild soap and water. If you do it at night the brush will be
dry by morning.