After playing through a few times, my advice is to embrace manifold layouts because they are easy to set up and even easier to expand (especially with blueprints). Pick a recipe to work on, and for each ingredient dedicate a line of producers to it. Do the same for the next ingredient, etc.

The key to this is that if (when) you need to extend your production of the goal recipe, all you need to do is add on to each line proportionally. Thus, you can set this up fairly early and just expand on it as you progress.

Note that you do absolutely end up making many lines of, say, iron plates and other early products; the goal isn’t to have only one line of each item, but rather to dedicate expandable lines to specific individual items (sometimes redundantly).

Also, the early belts do limit you and it certainly makes more sense to use load balancing rather than manifolds at that point, but you also don’t need to wait until the final tier of belts to start using manifolds.