Do you use harmonic exciters/enhancers and suchlike to get more going on in the top end?
Occasionally but with extreme caution. I ruined a lot of good mixes and nearly destroyed my hearing with too much Aphex or BBE back in the 90s and so I tend to approach them with care these days.
That said they can be useful for rescuing muffly drum loops or vocal samples.
I'd never insert one across a mix.