Combining a bunch of unrelated objects and stuffing their UVs into the 0 to 1 tile sounds messy and limiting. Considering camera angles and render resolution, having UVs set up like this means that all UV shells in that tile will take up only so much of any given texture resolution. A 2k texture containing a washer and dryer will mean less detail for both even if you managed to use every bit of that UV space. So yes, it's common to for an object to have it's own UV map.

As for materials, I don't bother with them when laying out UVs, well there are a few I use, some solid lamberts to mark what faces were projected and a textured lambert to test distortion. Other than that, material testing is a whole other process for me since the lighting conditions while UV mapping are unsuitable if not downright misleading so I have a swatch scene for that.

Also, I would say most definitely get familiar with Hypershade in the future . Creating some sweet shading networks aside, it allows you to work faster and make the most of the nodes.

Example : color/bump/spec maps for the same texture having their own 2D placement nodes that each have to be tweaked whenever the repeat values on one changes simply because the file textures were created with the map button in the attribute editor instead of taking 5 seconds of middle mouse dragging in Hypershade to connect all three files to the same 2D placement node.


Wow, that was a ramble lol.