There are several types of foundations to choose from. Mineral powder, liquid, stick, creme-to-powder and tinted moisturizers. Finding a good foundation for acne-prone skin takes some basic knowledge of the different types available, and knowing what will not aggravate the condition further. The most important thing to remember is to ensure the foundation is oil-free, and uses the most natural ingredients available. Some chemicals may aggravate the skin, worsening the condition.

A tinted moisturizer is the best option as it is water-based and allows the skin to breathe, especially important for long days. However, a tinted moisturizer will not provide full coverage, so a liquid foundation or loose mineral powder is a great option for a night out, or on special occasions when fuller coverage is desired. Creme and stick foundations tend to be heavier and may feel greasier on the skin as the day progresses, but there are oil-free options available.

Additional helpful tips:

Start with a thoroughly clean face. Use an oil-free cleanser, apply an alcohol-free toner, then the tinted moisturizer. Apply an oil-free lightweight moisturizer prior to using liquid or other types of foundation.  

It is best to apply any foundation with a clean sponge, as fingers may transfer dirt and bacteria to your face. If you prefer a foundation brush, clean it daily. You may need to apply tinted moisturizer with your fingers as the consistency is more watery than a liquid foundation. Just ensure your hands are clean before applying.

Use an oil-free concealer to cover pimples instead of relying on the foundation to do this. A small dot blended well will give the most natural results. Blending is key, ensuring it doesn't look too obvious. A light touch is best, as a heavy hand will usually just take off the concealer, requiring a second try. Choose a concealer closest to your foundation shade, as opposed to a lighter one you might use under the eyes.

Instead of using powder throughout the day to blot excess oil, use blotting tissues. The sponges used for powder are great at absorbing the oil, but you're also trapping the oil in the sponge, which you will use later. This can clog the pores and result in further breakouts.

If using a liquid foundation, a tube or a pump bottle are the best options as your fingers are not needed to get the foundation out. Simply pump or squeeze directly onto the sponge or foundation brush. These are also more sanitary options, eliminating a lot of exposure to the air and potential bacteria.

Finally, remove all makeup thoroughly before bedtime. Regardless of how sleepy you are, do not miss this important step. Your skin rejuvenates as you sleep, so sleeping with a clean, moisturized face is crucial at any age, for any skin type.