Some time ago Syp of Biobreak wrote a post with tips for Stardew Valley. I thought I might add some of mine to the mix in the hopes they might help someone else. Or at least help me if I take an extended break from the game and forget all of this. :p
These are things that me and a friend found out while playing the game and discussing it. They should all work with the current version of the game, 1.06, but if a future patch changes things I will update this post.
If you have any tips of yours to add feel free to put it in the comments and I will add to the list with the proper credits. 🙂
1) There is a pretty good planner for Stardew Valley on this site. This can be pretty useful so you can plan where you want to plant your crops, build your coops, barns and other buildings before you actually spend the time and money for it. It even allows you to see the range that the scarecrows work as well as the sprinklers. There is also an option to save and load your plans so you don't need to plan everything in one go.
2) When you upgrade your house to have a kitchen, you can use the refrigerator to put away your food (or anything else like any other container). The cursor won't change to a hand like it does for chests but if you click on the refrigerator it will just work. Even better, the food you put inside it will be automagically available at the stove, no need to retrieve it first to cook.
3) There is a place where you can cut down tree stumps for hardwood. The tree stumps also reappear every day so you can cut it down to your heart's desire. The entrance to the location is kinda hidden though so you will need to find it first. Hint: It is somewhere in the forest.
4) You can cut down trees outside your farm. They will regrow over time however in my observations the amount of time it takes for them to get back to maturity seems to be random. And unlike in the farm, leaving just the tree stump won't make it regrow faster.
5) If you find giant mushrooms in your farm you can put tappers on them. You can also put tappers in trees outside your farm including the palm trees in Calico Desert.
6) The ponds in your farm do not have any fish in it, only trash. However you can put crab pots in them and they have a chance to get fish as any other crab pot have.
7) When you donate books to the Gunther you will notice a book icon appearing on top of some of the bookshelves. That means there is a book there you can read. Just click on the bookshelf to read it. Some of the books are fluffy while others provide good tips. They can also be re-read as many times as you want.
8) If a speech bubble with a heart appears when giving a gift to someone that means you just gave them their favorite gift.
9) Don't worry if you forget your horse somewhere. They know how to get back and will be at their stable the next morning.
10) Bug meat can be used to make bait for fishing.
11) It takes 28 days for fruit trees to grow to maturity and they only produce fruit in their respective seasons. So plan for that if you intend to use those fruits to fix the community center. The trees also stay around forever unless you cut them down.
12) There are rewards for slaying certain number of specific monters in the mines. You can see which monsters, how many you have killed and how many you need to kill in a poster inside the Adventurer's Guild. You will get a message once you reach the required number for a reward too. Just talk with Gil (the guy in the rocking chair inside the adventurer's guild) for your reward.
13) There is a Traveling Cart that appears every Friday and Sunday in the Forest. You can buy out of season items from the lady there as well a some unique items. Her stock changes too so it is always a good idea to check on her from time to time.
14) If you ignore one of the citizens of Pelican Town for too long your relationship with them will decay. It is only a small amount though and that can be easily fixed by talking regularly with them again or giving gifts they like *.
15) When you get 4 candles in Grandpa's shrine (you will know when it happens) check it out. There is a good surprise in there. 🙂
16) When everything else fails, the Official Wiki is your friend.
17) If even the wiki can't help you try the Official Forums.
* As of patch 1.07 this doesn't happen anymore if you have maxed relationship with one of them. I haven't tested it yet with non-maxed relationships though.