Fusion 360 Design Best Practices Question (Am I on the right track?) So I've designed a few components in Fusion 360, but I'm kinda new to CAD.  I did the tutorials AutoDesk have on YouTube, modelled an Arduino enclosure, a shampoo bottle, a lamp shade, etc. but what I'm doing now isn't as straightforward...
Before I used to create solids, but what I'm doing right now is essentially a flimsy plastic part, just a sheet of plastic with a rim, and some other &quot;rib&quot; features, and doing solids you have to make a sketch, and every line has to be doubled because of the thickness of the material.
Today I'm trying surfaces after being clued by the &quot;Thicken&quot; command, I figured maybe that was more efficient, but I'm not sure if I'm on the right track.
When I work with solids, I end-up with the option to join whatever new feature to the main body, but with surfaces I end-up with a bunch of bodies that are essentially supposed to be one, and I don't know how to join them together after.
I guess they could be put together in a &quot;component&quot;, but I think components are more like a nut is a solid, a bolt is a solid, and a component is a nut and a bolt, not a bolt head, and a threaded cylinder...  So the way the software is made right now at this point, while it clued me to use surfaces, now it's cluing me that there's something I'm missing, or nor doing right...
There's no CAD Stack Exchange site, and I realize this might be a bit specific, but the part is to be 3D printed, I bought a new 3D printer not long ago for a project, but I need to get better at CAD before I can make it...
Attached is a screenshot of what I worked on, it's paths that I've extruded to create surfaces (tall edges), thickened those surfaces to create bodies, patched some surfaces to fill areas, thickened those as well (ended-up with stair-shaped corners that I fixed somehow), then I cut some bodies from the bodies below to end-up with that you see now...
I think I'm on the right path with surfaces, but I don't think my workflow is right, and I was wondering if anyone could help me...
Right now, there's supposed to be two screw wells in two corners of the circle, essentially wells with a hole in the bottom for a thumbtack to go through, and there's going to be a cap to cap it off, it's kind of the same process as what I've done so far, but like I said, I don't think I'm doing it right...
Ok, let's go down the main two ways to a part, and in practice you usually use both to design for 3D printing. Only for machining, you try to keep to the cutting method only.

Cutting Method
Building Method

Cutting Method
You start with a piece of &quot;stock&quot;. A cube or cylinder created by extruding the simple shape. Now you go and create profiles that you either extrude into the part or rotate around the axis - your profile &quot;cuts&quot; the &quot;stock&quot;. When doing this, you think of parts like a machinist: you remove the material as a mill or lathe would.

Buildup Method
You start with the profile of the piece, then extrude it, then add the next detail and so on. I work a lot with that, and you can have a lot of sketches in the end: