Stardew Valley/Later Years

Your goals for later years depend not only on what you've accomplished so far, but on what you enjoy doing in this game. Try to arrange things so you can do more of what you enjoy. It's hard if not impossible to pursue all the late game achievements at once - go for your favourites.

If you like milking cows, then consider building more barns and setting fences so you can keep track of the animals. If you like going mining, then you want automated sprinklers and pigs - or possibly no barn at all. If watering your crops gives you satisfaction, then you won't be so keen on the sprinklers; if harvesting your crops is the good bit then you may not be interested in saving up for a Junimo hut. If you like fishing, the Master Angler achievement may be the one to aim for.

Setting up sprinklers and other elements of automation is generally going to help you make lots of money while still having free time to go around socializing or fishing or courting. This is also a good path if you want diversity in your gameplay, as it means you have time free from farm tending to turn to whichever other endeavour suits your mood. (You'll still have to plant and harvest some of the time.)

Goals you are likely to pursue in the later years are:
 * Mystery of the Stardrops: Collecting all Stardrops
 * getting a supremely happy spouse (which means getting married)
 * A Complete Collection (donating every possible thing to the museum)
 * Master Angler (catching every possible fish)
 * PolyCulture: shipping 15 of everything.
 * Legend: Earning 10 million.
 * The Beloved Farmer: getting a 10 heart friendship with 8 people.
 * Gourmet Chef: cook every recipe.
 * Craft Master: craft every item.
 * A Big Help: complete 40 'help wanted' requests.
 * Full House: married with two kids
 * Master of the five ways: max out all 5 skills
 * Protector of the Valley: complete all monster slayer goals.

You may also be interested in getting the special dwellings from the Wizard: the Junimo Hut (will harvest crops for you), the Gold Clock (stops mess and decay), the Earth Obelisk (teleporter to the mountains) and the Water Obelisk (teleporter to the beach). The Return Scepter, available from Krobus in the Sewers, is another 'make my life easier' Item of Exceptional Cost. All these require, primarily, a million dollars or more.

For most of these objectives, you want to develop your farm so that it makes lots of money with a minimum of effort.