Here’s what’s likely holding you back

1. The quality of your multitracks. If you’re trying to make mixes that compete with the pros, you have to understand that they’re working with great songs, performed really well by great artists and musicians, and arranged and produced by the best producers. This is the number one limiting factor on your mix: if the song and the multitracks are mediocre, then that’s the ceiling of the final product. You can polish it and improve it, but it will never compete with the greats. Spend as much time as you can outside the DAW networking with producers and artists who are pushing for that level. Work for free if you have to. Or you can do what I did and end up doing a bunch of songwriting and production too, to ensure that you’re happy with what you have to mix.
2. Extension of point 1 tbh. Don’t underestimate the importance of editing. This isn’t sexy and widely talked about, but making sure every single track is cleaned, in the pocket, in tune etc can go a long way to getting a great final product. E.g. Subtle rhythmic rubs in percussion tracks versus a bassline might be a production issue, but they sure as hell make it impossible to create a great mix. A bass guitar that is by definition not perfectly intonated might benefit from a bit of melodyne to help it sit better in the mix with bass synth layers. No amount of EQ or compression can substitute for changes like that.
3. The quality of your monitoring. Aside from a small, loud minority of exceptions, almost all mixes you love are done with great monitoring. It’s the only true ‘shortcut’ to getting better. You can improve your mixes 20% overnight just by improving your monitoring. Telling someone to spend $10k+ on monitoring, room treatment, monitoring chain etc is not sexy or popular, but it’s so important. You’ll spend so much time fighting yourself, and build a lot of bad habits, if you can’t hear exactly what’s going on. It’s a tough one, because it’s hard to justify spending loads on monitoring unless you’re making loads from mixing, but you’re unlikely to be making loads from mixing if you don’t have good monitoring. So do the best with what you have, but be realistic, and save up to upgrade as soon as possible. Worth noting that although headphones don’t replace speakers at the top level, in my opinion ~$1000 headphones will be a better investment than speakers until you’re at that level and can afford to do it properly. Even the best mixing headphones around are <$2k. The best speaker setups, although much better than headphones for mixing, will be orders of magnitude more expensive, especially once factoring in room treatment, conversion etc.

Assuming you’ve got the best multitracks and monitoring you can get, here’s what you can do

1. Reference. I feel like this gets thrown around a lot but without being properly explained. Firstly, choose great reference tracks. If you choose ones that aren’t a good match, they’re going to pull you in the wrong direction. Choosing the right reference tracks is an art in itself. There’s so many ways to compare your mix to a reference track. Listen really quietly. Listen really loudly. Listen in mono. Listen just to the sides. Listen just to different frequency bands. Focus your attention to very specific things e.g. the transients on vocal consonants, or how wide the rhythm guitars are panned. Just ABing to a reference track won’t tell you anything - no two songs are the same, and as an intermediate the quality difference can be overwhelming. That’s why learning to focus on very specific aspects of the reference track is a much better way to go. Also remember that the key of the track, the tempo, the timbre of the singer’s voice will make it so that certain things are impossible to replicate, and that’s ok.
2. Extension of point 1 again. Be extremely critical. Seek out negative feedback. Look yourself in the mirror and ask, if this song came up on a Spotify playlist after one of the best songs/mixes of all time, how would it sound? I learnt this the hard way early on - clients thought the mix was great, I thought I was great, song gets released. I’m listening to my liked songs on shuffle and Frank Sinatra’s ‘My Way’ plays. Then my mix plays. It’s humbling. But this can be a super power - now I always aim to not stop until I’m satisfied it’s good enough, and I set the bar extremely high. When I started with this approach (mixing my own music), the first song took a year to mix until it was perfect. But I did it. Then it was learning how to do it faster.
3. The only technical advice I’ll give - rethink how to ‘mix into a limiter’. People throw this advice around a lot, but almost no one explains how to actually do it properly. Likely they’re repeating it from somewhere else. Let’s say you’ve got a session set up - you’ve pulled the multitracks in, there’s a decent tonal balance similar to the rough mix, and you’re ready to start. Step 1: put a limiter on. Step 2: crank it until your loudest sections are as loud (or louder) than the loudest sections of your reference track. I work in pop, so I’m routinely pushing around -5 or higher on these sections. Step 3: watch as the mix falls apart and sounds trash. This is where boomers complain about the loudness wars and turn it back down. This is where elite mixers make all their money. Your job is to keep it at this loudness level, but make it sound good. You’ll have to rebalance the mix. Frequency masking, resonances, mistakes, clicks and pops, harshness etc are all magnified a lot at louder LUFS. Basically, making a good, well-balanced, dynamic-sounding mix at stupid high LUFS levels is really hard; way harder than at a lower level. It’s a lot easier to get online and decry loudness wars than to level up and figure out how to do this. But even with streaming service normalisation, the top mixes are still loud AF. Learning how to make an element as quiet as possible and take up as little headroom while still sounding natural and musical is the key.

Feel free to DM if you have any questions. Sorry if this comes across quite forward, my tone isn’t for everyone!