Every time I go on this forum, I see many people talking about tantrum spirals. "I loosed my fortress because of a tantrum spiral" "Population is now down because I got a tantrum spiral" etc. And I find that ridiculous.
So here is a very basic tutorial on ways to keep you dwarves happy.
Let's start with the basics. Dwarves like to sleep, eat and drink. That, is important.
Sleeping: Do not use a dormitory. A dwarf gain an happy thought every time he sleep in a good (a.k.a. not so terrible) bedroom. How to make a good bedroom, you will say? Dig a 3x3 room with walls around. Put a door at the entrance. And then: happy thoughts. BONUS: put the bedrooms in one alone z level. It will help you to manage your space and your dwarves will be less ennoyed by sounds.
Eating: There is two ways to improve this part. The first is the easier, the dining room. A dwarf is happy when he eats in a good place. To make a good place, dig an big room (maybe 15x15, bigger?) in rock. Smooth and engrave this stone, and then put tables and chairs from an average material (any stone with 2 or more of value can do it) in the room. Some people are doing one table/four chairs, but a dorf get bad thoughts when he dine at a table with some one else. So, be sure to have enought tables and chairs to make every dwarf able to dine alone (30 chairs/tables for 200 dwarves). Place some statues and BOOOOM! Happy thoughts. The second way is to cook food with a skilled cook. Watch out, it will destroy plump helmets spawns, so if it is your main food ressource, you might not want a cook.
Drinking: Every one know that dorfs like booze. But did you know that many kinds boozes is almost as important as having at least one kind of booze? Dorfs like the variety. So, if a dwarf can drink between two kinds of booze at any time, he will be happy. But what if you get three? Four? Happy thoughts. Dorfs generally have one favourite kind of booze, so if you can manage to have a constant supply of every kind of booze disponible (there are always two kinds of booze you can't get. Check the wiki), you will have VERY happy dwarves. Even better: Sunshine. Sunshine is a kind of booze that you get with sun berry, a crop that you grow outside on good biome. Sunshine is 2.5 times better than any booze that you grow inside. Does this mean it could be worth having to make a safe zone to grow it, place mud on it and be sure to keep it rolling? Hell yea.
Now, advanced things:
A dwarf like high value things. He get an happy thought when he see: A good door, a good bed, a good chair, a good table, a good statue, a good floodgate, etc.
What does this means? Design your fortress to place good crafts everywhere. A gold statue in the main traffic areas, galena door in around your meeting area, etc. can be a good way to make dwarves happy. But, you can have more imagination. Lets think about an artifact... Of course, it's bullshit. You remember that legendary wooden door? The legendary gabbro mechanism? Find them a use.
You may of course want to trade them but... Let's think about it. An dwarf will be happy every time he pass this door or use this lever. Are you sure you dont want them? Really?
I might make more tricks in the future, but if you are intelligent you can have ecstatic dwarvesall the time with this little page.
NOW STOP CRYING ABOUT TANTRUM SPIRAL!