When I compare my mixes to professional ones, mine sound claustrophobic.  If I'm listening on headphones it always sounds as if everything is too close to my head no matter how much reverb or delay, panning  or anything I use to try to create dimension.  It sounds as if my listening environment is within a small pup tent and I'd like it to sound as if I'm in a much larger room.  When I listen to pro mixes it seems as if there's plenty of room for everything to spread out as if my listening area