Thank you Herb. I'm glad that you reminded me that I left off a very important aspect to the art of reverb. That reverb is decibel cumulative. That is to say every decibel of reverb adds to the overall decibel level of the track that you put it on. So when you increase or decrease the send level to the reverb bus it affects the level of that track in the mix. So as you add reverb you may have to lower the track level.

As to working with reverb in a song it's like any aspect of mixing. You have to practice. A lot. I took my cues from studying Dave Pensado on his "Into The Lair" series. He uses a ton of reverb in his mixes. It just doesn't sound overly wet because of how he handles the decays and how he eq's the frequencies and on and on.

There is more than just depth perception that can be achieved with reverb and slap-back and delays.

Experiment and have fun!