Mix & Mastering
If you want a good master it is important that the music mix is good, we always say that if you have mix on a point 6 on a 10 scale, you're master will be 7 or 8 point, therefore the mixing process is very important if you will get a good master, here we will say everything in the process of making music is important, all the way from the right string on your guitar, microphones, recording, gear, and on on on, you can't hide if you don't use the time it takes for making it right.
Now to the point, :-)
If you want a clear mix with transparency, space and headroom, you can use lot of cutoff in the bottom " bass frequency " for example you have a kick drum on one channel, and a 4 string electric bass on another channel, and then a jazz guitar on the third channel, then you can let the kick drum go all the way down to 20 hz,the bass you cutoff at 40 hz, and the jazz guitar you cutoff 80 hz.
Here you can see that in bass frequency the Kick Drum go all the way down, and bass and jazz guitar have been cut in the bass, this will clear up your mix, of course you shall do this on all channels and you can even cut in high frequency too, not only in the bottom. It's all about you only have to hear the sound of you instruments, not the mud and noise, every little thing even mud and noise steal space and headroom in your mix. Of course sometimes, especially in jazz or acoustic music you might prefer to have these noises in your music to give it warmth and atmosphere, so again there is nothing right or wrong, you must rely on your ears, that's why so much music is so different.
All these are examples, you must try to get you own mix with different frequencies on different instruments.
Try it out, music has to be fun to you, and when you first really get the music in your blood it is like a virus - you will not get rid of it :-) Remember: All the great old artists like The Doors, Pink Floyd, and many many more were experimenting all the time.
Have Fun :-)