Three - five years
Because these sorts of products contain alcohol, they tend to have a longer shelf life. Keep them in a cool place away from heat and they should last you well.
Eye and lip pencils
Keep your pencils well sharpened and with lids on and they will love you for it
Scents will last you 2 years if you look after it well. As pretty as it looks on your makeup table - the sun can cause it to go off. Fragrance needs to be kept cool and also in a dark place - in a drawer is a great home for it.
Foundation and face powder
Hopefully if you have a fave, you will be replacing it more than every 2 years, but that is the length or the time it will stay good for. Occasional users can rejoice.
One year or less
This is one of the shortest lived beauty products.To avoid major irritation and also cross contamination, always replace your mascara every 4 months.
You can get away with washing them a couple of times, but they can be a great breeding ground for bacteria, so buy bulk lots and replace every few months to avoid a breakout.
Wash in mild soapy warm water every few months to keep brushes in good condition.