What is the best way of making contact with civilizations you don't have contact with yet? My current fort has no contact with friendly humans or elves so I'm getting no seasonal traders outside my local dwarf civ.
Is the tribute mission the best way to do this? I'm looking to remain as neutral as possible with them. I want good relations with them to get wagons quickly.
Also, how do tributes from evil civilizations work? I'm down for some !!SCIENCE!! with some goblins or kobolds but wasn't sure if that would increase the amount of sieges if I demand tribute from Goblin sites that don't know about me yet.
Tribute mission is the best way, because you will receive the regular caravans from elves, humans, dwarves this way. I do one-time tribute, so far it never failed me regarding these types of civilisations, they will start both caravans and diplomats. I don't know how regular tribute works, one-time tribute is brought by your soldiers.
Sending to kobolds triggers a war (though they do not siege or even send thieves to me so far), sending to other types (single site govs) can result in tricky situations. I've send to a civ which also has a tower associated, the civ started caravans, but the tower sent a siege led by a monstrosity, with a team of intelligent undead and zombies. Which was my first undead siege in this fortress, after eight years of existence.