You should obtain this achievement somewhat into your first Winter or second year. Besides planting the profitable crops in Spring, Summer, and Fall, remember to use your Winter wisely.
Fishing and mining are some of the better ways to make money during the Winter.
Farm animals are also a great source of income, so ensure you're prepared to care for them before the season starts (grass and bushes do not grow in Winter.)
Peruse the land for
worm tiles.
If you have your Greenhouse built, fill them with Cranberries for the most profit and then Ancient Fruit later on.
NOTEThis achievement is related to:
Greenhorn: Earn 15,000g
Cowpoke: Earn 50,000g
Millionaire: Earn 1,000,000g