I didn't find it in the search bar, but essentially here is the strat.
1.Buy some cards that might help you early. You only really need to reach 5 coins, but reaching 8 can be nice as well.
2.Once you feel somewhat comfortable, start buying annex every time you can. Completely empty the Duchy pile. Cards like duplicate can help you with this. Remember to use annex to continue to buy annex
3. Buy all the dukes. If your opponent doesn't catch on to what you are doing every duke will be worth 8 VP each.
Reply with any flaw/way to improve this strat.