High and low EQ cuts
A lot of producers get rid of unwanted low end to help clear up a mix but often overlook the top end.
Take the time to cut high frequencies too, as treble can often build up creating a bright yet crowded mix.
From around 10khz upwards is mainly hiss/noise which can be reserved for the very brightest of elements such as hi hats, for example.
Other sounds such as guitars and synths don’t need all that top end detail in most scenarios and can ironically sound cleaner with hi end cuts. In turn this will make space for top end detail and your mixes will sound less congested and open.
Clarity is obtained from space rather than lots of bright top end.