Plates will be your new best friend. And stay away from convolution. You'll need a sound that you can sculpt.
he he - I find this amusing. A real plate was pretty much a one-trick pony. Some were adjustable, but essentially they were just a plate of metal with transducers attached - not really something you could sculpt the way you can tweak an algorithm. Sure - you can delay and eq the sends etc. But the reality is that a good convolution impulse of a real plate is actually far more sculpt-able than the real thing.
Digital algorithms often need to be tweakable just to get them sounding ok for different source material - some frequencies can expose nasty flutters - something a real plate doesn't suffer from.
Anyway - my advice is to try mono reverb for adding depth. Most digital reverb is hard panned stereo - which can give a nice WIDE effect, but WIDE is very different from DEEP. Especially with plugin reverbs, my advice is to always check how they collapse to mono - because there are some real ugly sounding plugins that are highly embarassing when mono'd. Good hardware doesn't suffer as much from this problem - but always check. With all but the very best hardware (I love my Bricasti
M7), digital verbs are often struggling with the resources to produce enough delays to create a smooth reverb. This tends to be more of a problem with drums or sharp transient material. So quite often you need to tweak the parameters for individual sources to hide any ugly resonances.
Some more random advice about reverbs:
If your algorithm gives separate Early Reflections and Reverb models, try isolating them to hear exactly what they are doing. Often I may remove the ER's and just use the Reverb - or the opposite, just use the ER's. If using plugins, you can mix and match - take a good sounding ER and apply a good sounding Reverb tail. Or use a delay plugin instead of ER's. Etc.
You can use a vibrato/flanger/chorus plugin to modulate a static convolution sample or a reverb that lacks modulation (try both send and return - slightly different effects).
Stereo width plugins can be very useful - not just for expanding the width, but for narrowing or mono'ing as required.
With delays - if you time the delay to the tempo, it becomes less obvious (the repeats get covered by drums etc), and you can create a lot of space without it being too obvious it is a delay effect.
Automate - keep it moving.