Here are the rules:
Mascara: 3 months from opening the tube. Gross bacteria accumulate, toss it!!
Blush: Creme cheek color, 1 to 2 years. If you have acne or any other skin condition, 6 to 8 months safe bet. Powder can last longer, 2 years, but if you have said conditions, clean with dry tissue 1x a week
Foundation- Liquid: Up to one year unless it starts to look funky and smell. Creme: 1 year
Powder(dual finish variety) 1 year.
Lipstick: If you take good care of it, 2 years or more. Once you smell that oily smell, toss it!
Gloss: 1 year(If you have any type of cold sore, toss all lip items you used before the outbreak.)
All pencils for face: Sharpen before each application (tip: Keep them in the fridge to get a good sharpening action.) Again: Toss any item that may have contributed to a sty or any other infection.