1) Spot clean your brushes after every use to make sure you're not mixing colours or leaving bacteria on the brushes. Deep clean your brushes once a week to ensure that they are kept hygienic. A good you tube video i watched, and now the cleanse routine i use for my brushes, is SWalkerMakeup.
2) Always make sure your foundation suits your skin colour, and make sure you blend it down your neck as well. You don't want to be going out with a line where you have stopped your foundation at the top of your neck.
3) When using a bronzer to contour, use a matte bronzer over one with shimmer. A bronzer with shimmer will reflect off the sun and won't give you the contoured look that you are after.
4) Curl your eyelashes before applying mascara, this will not only curl your lashes but will open up your eyes and make them look bigger.
5) Always carry a pressed foundation in your makeup bag to pat on your face during the day to control shine and to give your face a matte finish.