How Do You Get a Good Mixdown? Here's 1 Pro Level Top Tip that'll make the biggest impact.

Here's a quick trick that'll help your mixes breathe better and increase available headroom when it comes to the final master allowing for higher final limit levels.

High Pass those low frequencies!

Hi Hat Curve eq
Above picture shows a simple hi hat. We can quickly see the expected sound energy up top 6k up.
What's surprising however is the amount of inaudible low frequency energy present. This low frequency content is adding nothing to the timbre of the hat itself so can be safely removed.
I always recommend going by ears rather than eyes, in doing so we find we can push the low cut to around 350hz before it starts to have an audible effect on the hi hat.
Once you hear it starting to cut into the timbre of the sound itself, dial it back some then settle on that.
If you're monitoring system is less than ideal then as a general rule you could safely cut up to 100hz / 120hz on the majority of non bass related sounds.
The above represents 1 hat on 1 track. Multiplying this across dozens of additional tracks then it quickly adds up, muddies the low end, affecting track dynamics, squeezes out available headroom and negatively affects the ability to get a clean mix and good final limit.
Simple, effective and so often overlooked or ignored. Start trying this on new and existing tracks and you'll quickly find the track breathe better and open up more.