One of the most important things to me in makeup is sanitation. I have worked with several makeup artists that completely grossed me out and I swore I would never repeat their habits in my makeup artistry. For example, I had one makeup artist drop a brush on a public floor, pick it up and continued using it like nothing happened. I had another makeup artist that used lip gloss and applied it straight from the application tip, dipped it right back in and used it on the next girl. Uhhh, that just gives me the heebie jeebies.
I always use disposable applicators when at all possible. I always cut off lipstick, place on a disposable palette and then apply with a sanitized lip brush. It is more costly, but to me it is worth the benefits of keeping my clients safe.
When Good Morning America did this undercover report, the findings were a bit shocking, but it goes to show how important it is to be sanitary with beauty products, especially if you are a makeup artist.