Hey @John Eric, I think getting the bass right is tricky for a lot of people, but there are some things you can do to help get a good sound that translates well to different playing environments.

I would suggest looking at how you EQ first, and then sidechain compression with the kick, and then look at combining multiple bass sounds together.

Low Bass & Mid Bass Presence
The main idea is to have TWO places on the spectrum where the bass is prominent (this goes for kick, snare, vocals, probably lots of other things too, they just different spots along the spectrum). You want to emphasize the fundamental, which will typically be in the 50 - 100 Hz range, as well as a place in the mids, which could be 1k Hz for attitude and to cut through the mix, or 2k-2.5k Hz to bring out presence. This is important because a lot of playback systems lack the low bass, so the mid boost is the part that people will actually hear. It also helps on a good system because the human ear is tuned to pick up the 1k - 3k Hz range the most, so adding a bit in there ensures that it can be heard.

Kick & Bass Interplay
You'll also want to make sure the kick and bass aren't competing with each other. Decide which instrument is the lowest, and which is the second lowest, and do some complimentary boost/dips to allow each to have their own place. For instance, if you've got a kick with a fundamental at 60 Hz, do a dip at 60 Hz on the bass. If the bass has a lot of notes around 80 Hz, boost 80 Hz on the bass and dip 80 on the kick. You can also do some sidechain compression so that the bass is compressed a bit whenever the kick hits.

Bass & Guitar Interplay
You can do a similar complimentary carving between the bass & electric guitars. This is more helpful in some genres than others, and is particularly helpful if you've got heavy guitars playing low power chords. Make sure the bass is playing lower than the electric guitars, and on the guitars do a dip or a high pass filter to cut out where the bass is playing. Then on the bass do a dip where the guitar fundamentals are (maybe 100-300 Hz). The ranges may vary depending on the style of music, but just apply the concept of giving each part their own space and making space for the other parts.

Combining Bass Sounds & Clean vs Distorted Bass
You can use two separate tracks to combine two different bass sounds together and give one of them prominence in the low fundamental zone, and the other one prominence in the mids. Make the lower bass cleaner, and the higher bass overdriven. One problem some people have is using one bass that's too clean. If it's too clean, it doesn't have much harmonics going on in the mids, so it's hard for it to cut through. Adding distortion creates higher harmonics, and so those harmonics come out in the mids. If you use just one bass track, then you definitely want some distortion or even mild overdrive to give it more mids, otherwise there's very little to bring out with a boost.

EQ Cuts
Since you mentioned your bass being "muddy", that's typically used to describe a sound that has too much low-mids. Try a dip between 150 - 300 Hz to "clean up the mud." If the bass sounds too "boxy" then try a dip between 350 - 700 Hz. If it's too "woofy" then you'll probably want a low shelf or a high pass filter to reduce anything lower than the lowest note the bass plays on that song.

Conclusion
I know that's a lot of info to take in, because it's hard to diagnose the problem without hearing it. Just take it one step at a time and maybe start with any steps you haven't tried before. It may be that just one of these steps is needed, or you may need to use all of them. It really depends on the song and the mix, but experimenting with these ideas should get you in pretty good shape!

Good luck, and happy mixing!

so usefull, you are amazing!

@Leaf Colors wow thanks this is very helpful

@Leaf Colors this is incredible! thank you, I am definitely applying all of these tips to my songs from now on

dam leaf colours thanks for taking the time to write that out. I'm legit writing that shit down ha-ha.

just wanted to add that layering a bass and a lead isnt wrong at all. there is nothing ‚wrong‘ really, just things you can do that bring you further away from what you want.
What you can also do is make the top layers very
silent so they just add some texture to a bass that is primarily in the lower octaves. add some saturation, follow the steps above and the badd will come to live (it‘s a bit Leaf Colors wrote in the combining part)

keep on making music<3