This tutorial talks about a scene done in cinema4d, but most of the ideas can be used in any 3d program.  

Beginner

He briefly explains the modifiers in 2.8.

Cool uses for several modifers.

Constraints

Beginner

This person has some great ideas on how to use constraints to keep an object to a path, rig a piston, rig a jet exhaust,  He uses the snap to curser shift s keyboard shortcut.  He has some parts which don't constrain properly, and he shows you how to fix those issues.  

Beginner

Intermediate

This person from decoded has all the basics of making a room.  He explains how get the camera settings  from a thirdparty plugin, and how to make the room, furniture, and lighting.  If you do this tutorial you should be able to make a very nice room.