Firstly, there are no set rules. Instead, probably the best thing to do is pick up tips here and there and combine that with a decent commitment.
Here's a few of mine for what it's worth, in no particular order. Not everyone will agree with all of this.
1) be ready to find that it takes a long time to get much better. Some people do very well quite quickly, but this is the exception not the rule. And of those, they usually find they meet stumbling blocks too eventually.
2) Put aside senseless pride. Most of us start out thinking we know this or that, but only start to make real improvements once you begin listening critically to other people's music, and their technical advice. Don't be afraid to try new things, even if you've always done something a certain way.
3) Time is important - you have to work out a way of working reasonably quickly. This isn't something which is just true for professionals, although they have learned this. When you try any new technique you'll go slow at first, but be conscious of it. Part of improving is in completing tunes, and the rate at which this occurs has some bearing on how much you eventually improve. This is coming from someone who is a relatively slow worker, but I think it's important to finish stuff, or at least occasionally start something new. Essentially, refining your workflow has an impact on the quality of your music.
* Put aside a regular time to work. As much as you can reasonably afford without killing your interest or jeopardising your other priorities.
* Train your ears. You think you can hear what a good mix is to begin with... this is usually a bit misguided. The best way to establish this is to critically listen to other people's tunes (which achieve a sound you're interested in), and work out how to do that. You can even import other people's tracks into your own projects, to hear it along side of yours.
*This is NOT
about copying them. It is about training your ears to hear the crucial differences between a track by an experienced producer and your own efforts. Remember music was always something meant to be learned from and shared with others.
The thing is even though we have different gear and a different mindset, what'll come out usually won't be the same.
You use what gear you have to aim at a particular sound that you're after. Because everyone does things differently, no doubt your process will be a bit different to someone else's. And in the end it might sound a bit different too, but learning the process itself will help you to make the most out of what you have, and that's what is important.
Well, that's just a few random tips. I'm sure others can expand on that.