I'll start:
I embarked on a pretty neat little world. The area that I'm in has a river, two swamps, plains up north and a forest down south, both separated by a mountain that runs horizontally across the map. My thinking is that I'll make a tunnel when I need to cross the mountain often, but for now scaling it each time I need to (which is never as of now) will suffice. Apparently there's also an aquifer on the chunk of earth I chose, but I consider that a plus because it means I'll be able to build a convenient inside well.
I started out by building some rooms, a stockpile and a carpentry workshop. Dug into the mountain from the north, because that's where the caravan was. Conveniently, so were the river and the fruit-rich fields, so I was up for a pretty good start. Cut down some trees, stockpiled the logs and started building beds and doors for the rooms. My dwarves started unpacking the caravan and putting all their stuff in the newly created stockpile, and they were getting accustomed to their rooms. at some point, a raccoon started pillaging some of our resources, but I built doors to the entrance of the fort and that seemed to solve the problem.
Then, waves of migrants came. I kept expanding the fort to accommodate more people, as we were now 20+ in it. I made a room for out manager so that I could carry out orders easily and I started adding some more workshops. Most of the bedrooms had polished walls by that point so that the dwarves would be happy about their living conditions. I tried digging downwards for more space, but I butted against an aquifer. I made lemonade out of the lemons that the game gave me and made a series of wells, which proved to be quite useful as I no longer needed to go to the river for water.
Unfortunately, despite all this good progress, one of the migrant's children was taken by a fey mood. I didn't really pay attention to it, thinking that, since a child can't do anything, the fey mood would just go away on its own. It didn't, and the child went insane, becoming melancholic. It eventually dehydrated itself to death, leaving behind two grieving parents. I built a stone coffin and a burial room to accommodate further deaths in the event that they happen.
Shortly after that little incident, a giant immigration happened, adding 20+ dwarves to my fort in one go, forcing me to change the labours of a few dwarves to help carve out some more rooms. I also had to build an extra carpentry workshop to make beds and doors faster. I am currently trying to make cloth so that I can make rope for some more wells, and hoping that I don't run out of room for stockpiles from the aquifer. Other than that, I'm doing good so far.
This is my fortress as of now: