One of the worlds most renown mastering engineers once coined a phrase like: "Mastering is easy - only the first 10,000 albums might be hard."
(Attention, I'm on my soap box now! 🎉 )
Mixing music is my main profession since more than 25 years now. Still I always try to avoid to master my own mixes (... in fact I would decline jobs which would oblige me to do so). Mastering is something that has to be done with a fresh approach, by a different set of ears in a different room, with a specialised set of tools, ideally by someone who has the experience from countless other recordings and their sound. Be aware that mastering is much more a technical procedure than mixing, where you can get by with trial and error to a certain degree, even if you have little technical knowledge.
On top of it, there is little chance that a preset will really cover your actual mastering needs (... as someone who created several thousand presets for VSL's product I hope that I'm allowed to say so 😊 ...). Refining the sound of a mix is usually achieved by the combination of dozens of individual, sometimes minute adjustments of carefully selected equipment.
In other words: You will have to train your ears for quite some time to grasp the Dos and Dont's of mastering. There's no real shortcut, sorry to say so. The best way to start is to do throrough "ref-checks", which means to make loudness-adjusted, gapless comparisons between the mix/master you're working on and a reference track (which you seem to have already when you're using match EQs). Try to put your finger on the actual differences. Try to differentiate between all the possible dimensions of sound (volume vs. loudness, frequency contrasts vs. melt, fundamentals vs. harmonics, transients vs. density, coherence vs. width vs. depth, etc. ... and all the constantly moving targets of "taste", "style" and "flavour of the month 😉 ...). Now you can start to reach out for the right tool to close this gap.
(... and if it's really important: Ask a professional mastering engineer to work on your mix! 😉 There's nothing wrong with it.)
/off my soap box again 😊
Kind regards
/Dietz - Vienna Symphonic Library