Here's a great process when applying a broad range of tones to a single track or a full mix.

I don't remember where I read this, but the technique is called EQ Feathering.

Rather than applying a large amount of EQ at a single frequency, add small amounts at the frequencies adjoining the main one.

In the screenshot below. Instead of adding +3db at 100Hz, you add +1.5 at 100Hz, +.5db at 80Hz, and 120Hz.