From the title you can guess that I believe that it's important to finish your tracks, right ?
Throughout my music life I encountered, worked with, lived with people that weren't able to finish their tracks or songs. Often times people that were starting out with music making but also people that were somewhat established or coming up well within their music scene, at least had a bit of momentum going on and could have gained further popularity...hadn't they had that "problem".
It doesn't really matter if you're doing techno in your bedroom, recording acoustic guitar and vocals in your bathroom or trying to create a song as a band. If you only start projects and then keep abandoing them before they're finished, you'll probably never get to a point where you want to present music to an audience, let alone release some of it to the music market. And you will never experience something that I believe is extremely important for creative people, at least in the music industry.
There are people who choose to postpone progress on a track/song or a creative process in general because:
they keep coming back to the bassline (or what have you) and can't move on to some other element (after three days tweaking that frequency already)
or they come to a point in the track where they decide to go back to already finished elements to avoid dealing with creative blockades (this can transform into a habbit)
or they're real newbies but want their production and technique to be just perfect, so they read "5825 ultimate tips to get EQing right" and study tutorial over tutorial but nontheless aren't able to make their first few tracks perfect (of course they will never achieve that) and just give up
I want to come back to that experience that I find to be so important for myself and which I think will feel important for everybody who identifies with it. I made my first 5 tracks or so in Magix Music Maker in 1998, I then fiddled around with the first Audio Mulch versions in 1999, then moved on to Fruity Loops and Reason and Logic (on Windows PC still) and Cubase until I finally found a home in Ableton Live from 2006 on. You know what I learned that I would never want to miss ?
I learned that I get better over time and learned to appreciate that.
A fictional example: In 2001 I learned that I made 5 shit tracks in 2000, all of which I had to throw out of the window now that I was better than I was before. And then same thing happened again and again, each time my creations were a slight bit better and progess was there but they were still cases for the trash bin a bit later, with only a little bit of hindsight on them. And you know how many times that repeated for me? For years on! You know why? Because I only made complete tracks. I learned about structure and arrangements, how to use time efficiently. I also only worked at one project at a time. I had discipline without thinking about it or forcing it. I built what I thought were complete works from start to finish, it was how I did things. Of course my results weren't any good at first. The production was terrible, the story lame, the mixing aweful and the style awkward. But by not being too much of a perfectionist in the beginning, I learned to move on from kickdrum to bassline to percussions and eventually to a point where I felt comfortable saying "Okay this one is done, on to the next one!".
It still breaks my heart thinking about the times I've seen or heard about people who fail to finish track after track 20-50% into them.
Bottom line is: Start projects and try to finish them even if your kickdrum or bassline doesn't sit 100% right. If you don't know how to fix that yet, don't pause to learn it but go on and figure it out after you've finished this track and then start the next and see if it's better. "Perfection" (doesn't exist anyways) but comes from honing that craft like a good sword. You're driving it to "perfection" over time by completing your work steps and doing them again and again.
Here's a principle that keeps spooking around in my mind from as early as I realized what I just wrote about, many years ago.
Imagine you're fascinated by Muddy Waters playing the Blues - or insert any blues legend - very likely he started out on a shitty guitar, he probably started out playing the damn thing in a crappy way, like we all would. But he came a long way and mastered it over time. And more importantly, he developed a style and feeling that he could only develop from playing on and not going back to that one moment where he missed the right note, getting stuck in that moment.
And there is something else to learn here. By early on focusing on making a piece of music instead of being a perfectionist and creating that specific sound exactly like you have it in your head, you'll become a music maker...instead of keeping trying to perfect that one sound years later.
Now go on and start all over for the last time and force yourself to finish that next track :)
ps. What can help when you feel like you always get stuck is to take another track/song that you love, a reference so to say, and pick it apart and learn from it about arrangement, structure, progress and the ins and outs of your favorite track. That's not copying if you don't intend to copy it. It's learning from greatness !