Reverb on the bass
Try it! It’s a secret weapon.
Not only does it add presence without adding extra volume, but the texture of the reverb can impart a wide range of subtle colors to the bass.
I’m partial to algorithmic reverbs for this sort of thing — they seem to add a special luster.
Do it as an aux; it works better than plonking the plugin directly on the bass track, because you can fine-tune the reverb treatment separately with EQ etc. Rolling off the lows below like 150 Hz is generally a good idea, and I often also roll off the highs above like 1500 Hz. Experiment.
Bonus power move: put a stereo-widening plugin on the bass reverb (here’s a good free one), set it to like 180%, and narrow the width of the reverb channel to like 55%. I know it sounds anti-intuitive — widening and then narrowing?? — but it gives you a great sense of width that doesn’t clutter the sides of the mix and is very mono-compatible.
Lushly — jamie