If you have the patience, drugstore makeup goes on discount in regular cycles. Usually at least one of the major chains will have buy one, get one half off on the brand that you’re interested in. Combined with sunday paper coupons, drugstore makeup can be a steal sometimes.
As for high-end makeup I only buy if there is a gift with purchase (a great way to sample high-end skincare) or when sephora has their site-wide discount.
Lastly, hautelook for great deals on the balm, Lorac etc and don’t forget to browse the end caps (clearance) at target and sephora!