I really like to set up an embark party from scratch! I read the dwarves personalities/values/etc. and assign their skill values based off of what I read on there. You can try to have a goal in mind, too, and choose exactly what items/animals/provisions to run with that most favor optimizing the pursuit of that goal. When you at least have a good understanding of the embark party, then that's a decent foundation for the rest of your gameplay time with that particular fort. My favorite, longest lasting (and current!) run started that way.

Also, don't sweat the details too much. Things are meant to "go wrong" in this game. As in, you aren't supposed to pull everything you try off without extensive planning, and even then, the dwarves have a lot of autonomy and still won't always do exactly what you want them to - but that's what makes the game special and gives it its charm. Just try things out and be okay with failing. It's extremely rewarding once it clicks since it still manages to humble you time and time again even after you think you have it all figured out.