Clear Skin

As it was already mentioned give your skin some rest once a week from any makeup or beauty products. Clean it with cleansing tonic and let it breathe for a day.
To conceal your pimple apply a bit of concealer (green-tinted if pimple is red) onto and around it and then blend well with the foundation. Avoid using too much concealer though as it may draw attention to your pimple.

Try using sheer and light creams and foundation. Apply moisturizer or cream only to clean skin.
Try washing your face with rose water or orange peel powder to reduce skin inflammation. Dry orange peel in shade for 4-5 days, then powder it very well. Use 2 times a day instead of facial soap.
Remember that pimple cosmetics has a short-term effect, so in order to eliminate the cause of pimples you need to know the cause and take a proper treatment, which may be slower but more effective.