1. If you make a mistake with your mascara, DON'T PANIC! I get mascara on my eyeshadow or below my eye all the time. Let it dry, and then use a Q tip to gently wipe it away. It will flake off, and no one will ever know you had any mishaps!
2. Always take care of your skin! It is our bodies largest organ, and should not be neglected. Cleanse twice a day, use a toner (I like witch hazel), and moisturize. Never forget your under eye area. This is where you will see first signs of aging. NEVER go to bed with your makeup on. NEVER!!
3. Use all of your cream products, then apply your powder products. You don't want to mix them, because you will end up looking so cakey and made up. The powder products set the cream ones, and keep them from moving or creasing. If you use a kohl/pencil liner, set it with the same color eye shadow. This will ensure that it lasts all day and doesn't move.
4. Don't line your bottom lash line only! I don't see this a lot, but I do see it from time to time, and it honestly freaks me out! It is just the oddest looking thing, and you may not even recognize what it is that looks so odd. It draws the eye down, and makes your face look droopy. If you are only going to line one lash line, line the top. You don't have to use liner at all, but if you don't, make sure you use plenty of mascara or false lashes. If I want some definition, but I just want to lightly line, use a smudge brush and eye shadow as a liner.
5. Don't use a lip liner that is way too dark for your lipstick. It looks so odd, makes the lips appear smaller, and in my opinion ages you. This used to be something we did in the 90's, but it's just not a good look. It flatters no one! Your liner doesn't need to be an exact match, but it does need to be similar to work.