There's lots of things you can do!
- Like Jonny suggested, listen to it in different environments and at different daytimes. This includes listening to your song really loud and really quiet. A general rule of thumb is that you should be able to spot every element in your mix even at the lowest audible volume.
- Especially with media music: have your music running to different images. You'll discover new things about your track and get fresh ideas that way.
- Reduce your track. The most common mistake when starting out with music production is doing too much. E.g. just have the percussion tracks running. Do they leave enough place for the rest of the music or is it already too much?
- Listen to your track in Mono! Not just because of compatibility, but also to factor out panorama from the complex hearing experience. A good track will sound good in Mono, too.
- Make notes on paper while listening to your track. Not in Word or Notepad, but with a real pen on real paper. This might sound a bit silly, but putting your goals with this track down like this will make you want to achieve them.
- This isn't really a trick, but don't forget to give your ears a rest. I like to leave my computer for at least once every two hours, maybe go downstairs, take a stroll around the block. No computer screen, no cat videos on YouTube, no other music, just fresh air and imagining how you'd like to continue with the track.