I have a simple system that works very well:

Never order anything online before checking dealnews.com; Takes 10 additional seconds, saved me thousands. Among other things, they give you every single Lenovo deal (including through the Microsoft Store, which is often better than the coupons in the Lenovo store -- and usually arrives within a couple of days rather than 3 weeks), and they give you the past deals/coupons, so you can see if you need to wait a couple of days to get a 30% price reduction -- Lenovo, and many other vendors, have 30% off in two out of every 3 weeks, or two days out of every week.