I think there so many things you can do to get nice sounding layers. A lot of what was said above is very agreeable, and to go a little further:
When you're EQing different layers: don't just stay aware of how your sounds will be when put together (clashes / what frequencies need to do what), but also be conscious of what the final layered product will sound like in the mix. Thinking ahead can help you get in the direction you're looking for.
Composing your layers also all depends on both A: What kind of sound in particular you are trying to make and B: How that sound compositionally translates into the style and region of music you are making (should sound familiar). If you're trying to make a thick and crunchy electro bass, then you probably don't want to overdo it with layering unless you are going in a very deliberate direction and are individually adding in all the harmonic elements of the bass separately (or something). It will most likely comprise of maybe a top and low end, which is completely fine; purity in the lower frequency range is usually ideal for most mixing scenarios. If you are, however, creating a very cinematic or epic pad of some extent, then that has greater room to keep adding sounds. The liberty to layer so much here is given both by the nature of what you are composing and where it sits in the overall spectrum of things.
And... Learn what others do! If you aren't quite sure of what sounds should be placed where, it never hurts to watch tutorials on how some artists you like layer things. To take it even a step further, I'd say that you should really research how it can be done. Just google how some symphonies arrange their instruments or find some classical music that you like. You can pretty much always find the music or even just watch the performers to see what instruments are playing at that rich melodic section and from there delve into what kind of harmonics and timbres are being produced. Or even performers in jazz, fusion, rock, gospel, funk, or any other kind of band or music that comes to mind. The experience from listening to good layering will help you grow as a musician to be able to hear what you want in these kind of situations. That said, you should also try to gain that experience a little on your own. Play around with sounds that you may not think fit together right off that bat. You aren't really guaranteed to get something you like but there is always the chance of finding something good. If not, at least you get closer by learning what isn't good!
...tried recreating the methods they use, but when I'm making my own stuff the sounds I come up with or even when I choose a few presets it never sounds right. Any tipsor tutorials?
I think this is also a function of the experience you get from producing. A lot of musicianship in general is about getting more accustomed to what you think sounds right, and then advancing beyond that point and forming new content and ideas.
original post edit note: I didnt edit this at all good luck reading lmao