Woodworking is going to be more of an assembly of lots of relatively simple parts.
This is tangential to your original query, but woodworking is my main application as well. I'd encourage you to think in terms of a multiphase workflow for each project - you can use Fusion 360 for a lot more than just the basic design.
I usually start by modeling the desired product without worrying too much about the actual construction details. For example, if I was designing a bookshelf and I planned to set the shelves into dados on the case, I wouldn't model the dados; I'd just add shelves that spanned the inner surface of the case. This keeps the modeling relatively fast and simple and facilitates interactive design. (And to your original question, yes, a shelf would be a component, since it's going to be a replicated element distributed according to user parameters.)
Once I'm happy with the overall design, then I ask, "OK, how am I going to actually build this?"
Phase two usually starts by merging a lot of the bodies generated in phase one into composite masses. For example, I'd merge the sides of the case and the shelves into one body. Then I'd draw profiles for the dados on the front and use them to slice a representative shelf out of that mass, producing a shelf board that is wider than the interior dimension of the case, plus two sides with dados. Those are the parts to be produced in the shop; they're the objects that will participate in the actual physical assembly process.
In phase three, I reconstruct the entire project using the parts produced in phase two. There's no modeling here, just assembly. This operation verifies that the phase-two deconstruction was done properly and that the original design has been faithfully translated into a manufacturable plan. You can use Combine operations (e.g., intersection or subtraction) to verify that the object built from parts has identical 3D properties to the original design. Phase three also gives you a chance to think about the actual assembly process, step by step. You go through it in the virtual world, which often reveals potential issues well before you get to real life and things are harder to fix (e.g., "Do I own a clamp long enough to let me assemble things in this order?").
In phase four, I worry about the physical process of producing each part. For example, I pull the end of each board out a little bit to allow for some waste. This gives me some room to trim iteratively in the shop, either to achieve accurate dimensions or to sneak up on a perfect fit through trial and error during assembly. The result of phase three is a raw cut/milling list. I dump this into CutList Plus fx, which tells me how to make those raw parts most efficiently from the boards and sheet goods I have on hand.
The nice thing about this layered approach is that it's all completely connected; there's never a point of no return. At any time you can return to the parts, or the assembly, or even the original design, and make changes. Yes, you may need to adjust parts of later phases correspondingly, but that's usually pretty easy.
Components are a critical part of keeping this all organized. Top-level components mirror the phases: Design, Parts, Assembly, Milling. Components within Parts, for example, are based on elements of the Design, but they also have their own modeling path that you don't want to mix up with the base Design. When you look at the Design, you should see only the components and modeling history relevant to that phase. The Parts phase clones in elements of the Design, and the Assembly phase clones in only components defined by Parts.
TL;DR: See rule #1. 🙂