So really in the grand scheme of things, I know fuck all about the technical side of mixing. Sure I understand the purpose of beat matching (yet cant properly

but there are some things I just cant seem to get my head around, or atleast think Ive come to understand well.
Things like EQs, So I mix a non vocal into a vocal, I knock the mids down on the non vocal right? but what about the highs?
Generally speaking, outside of cutting the bass on the 2nd tune, I have no idea what im doing with them.
Is pulling the previous tune out literally just a feeling in the end? like I find myself mixing things like grime for over 32 bars and it going ok and other times swearing out loud because had I cut the last tune off a bar ago instead of riding it longer It would have been sick etc
I do make mixes, well recordings of everything I do and if I like bits I give them stupid names and pass them on to friends, they ask me to make more but they dont really know what makes a mix "good" as they are just normal folk so I find it super hard to get constructive feedback on what Im doing, how I can improve and so on.
Heres the most recent as an example.
http://www46.zippyshare.com/v/19143794/file.html
It goes to hell at 20+ but Im like, I like it but is it actually "Good"
Anyone have any general tips for mixing as well? or any habits you have that help you out?