Combine Primitives to Create Object

In my opinion, creating objects with more than one piece has to be the HARDEST thing about unity. It's tedious to have to change views so much so you can line everything up. Maybe there is a little trick that I am missing, but I find it all difficult. Combining them is easy, but if there is a way to lock them together, I'd like to know. If there is, let me know, because I would always go to move an object and forget I need to click it in the hierarchy rather than the actual object and then I would take it apart and the software wouldn't let me use the undo option....so it was just AHH. Now that you've created more detailed 3d objects in Unity are there other types of objects you'd like to create now? Which ones? - I don't like the idea of making more detailed objects, but I will. I am going to make a water bottle and tire in my game though. I'm curious of how it's going to go when I make my building too.