Hi, it’s me with a newbie question again!
So, I’m trying to make a more complicated scene, and I’m trying to parent pieces of objects together so that they move and behave together, but I have a couple questions.
First off, I’ve seen some tutorials that put the different pieces of an object together in a collection, and just hold them together that way. Other tutorials use one piece of the object as the parent, and put the rest of the pieces as children of that piece. Some tutorials use an empty object as the parent to all the pieces of the object. And finally, some tutorials just union everything together.
So, unioning everything together seems like it could cause unnecessary difficulty when later trying to change the colors/materials of the objects, if the parts could be made of different materials. It also appears to make further modification later more difficult, as it is a destructive change
I can see using one piece of an object as the parent being useful if there’s one “major” piece of the object, and the others are smaller parts/details added on, but for some objects where there’s not any one main piece, it seems a bit contrived.
Parenting to an empty is what I have been doing so far, but it feels awkward, and I’ve had a couple instances of my empty literally just disappearing! The other issue I’m having with parenting is that for hiding/unhiding the objects, I haven’t found a simple way to select the parent and all children quickly. I may be doing something weird with this, though.
The collections seemed like an interesting idea, but it doesn’t seem to keep all the objects together when moving, and things like that?
So, what is the preferred/correct/ideal way to keep pieces of an object together? My current scene includes a desk with drawers, a chair, and a few other items that I’m trying to make in order to learn things better. The desk is where I have the most complicated setup, as there are lots of pieces involved, but earlier, my chair just literally disappeared completely. It was in the hierarchy window, but didn’t actually exist anywhere in the scene (I tried using the decimal point in the numpad, and that didn’t find it at all… it wasn’t hidden. And X didn’t even work to remove it – I had to unlink it? So it was like it had gotten into a weird state). Then, after I recreated that, I was looking at my desk, and I couldn’t do anything with the empty that was the parent of all my desk pieces. It could be selected in the hierarchy, but couldn’t be grabbed or rotated or anything, so I had to clear parent for all the pieces, create a new empty, and set all the pieces to the parent again.
Anyway, I’m sure there are recommended ways to handle this, but I’m not sure what they are, or why blender likes to play silly games with me. 
Thanks for all the help!