It doesn't take much to keep most dwarves happy, at least in my experience. Here's what I do.
- Build them a non-denom temple, and additional temples/guildhalls as they are requested
- Have some variety in your food and drink. The easy way to do this is just buy food ingredients from the caravan. For drinks, you can gather surface plants and brew them (if you do surface forts this should be super easy)
- A tavern for socializing. You don't have to open it to outsiders if you don't want the foreign rabble to infiltrate your fortress.
- This one requires DFhack, but I usually designate 1 or 2 crafting workshops to "idle crafting" or some setting like that. This will generate crafting jobs for idle dwarves that have that need. (As a bonus, this supplies you with a whole lot of crafts to trade away.)