If I have the option of mods, I'm going LTN every time. If not, it'll be 1-8-1s, duplicate names, one train per requester station, provider stations disabled by circuit if insufficient supply. No need for stackers - waste of space.

Once I unlock trains I pretty much tear down my base and switch it over to city blocks dedicated to individual components, each using 1-1 or 1-2 trains for inputs.

Usually start with 1-1s and stick to that.

Depends on the map and base, though. Never had a huge megabase that needed more than 1-2s with LTN mod

I go for 1-1 because I'm bad at trains so every line directly from a single ore patch to a drop off with no signals or overlaps on other tracks.

My last world used 1-4 train cars on a two way rail network arranged in a grid, with train station limits and circuits controlling the station to only be on when it had the right amount of resources. (Whether that be enough resources for an output station or low enough resources in an input station) this was enough to easily handle somewhere near 700 trains traveling between around 800 stations supplying a modular factory that sustained 5.6k spm. I stopped that file due to performance restraints, the train network was capable of much more. On my new space exploration play through I think I’ll stick with the same.

I tried building a grid with two-lane intersections, my trains weren't able to plan routes where they need to go around a grid cell and turn around (which was definitely possible without using the same rail twice), then I tried troubleshooting it for 1-2 hours and decided to give up on trains until I need them to bring in ore from far away.