1. Your equalizer or spectrum meter are your best friend when it comes to producing a song. If you don't have a spectrum meter plug-in you can cross reference your song by playing it in any music program like winamp http://www.winamp.com
By analyzing the EQ and its responses. Find the frequency range that is not jumping very high and fill it with sounds of the appropriate frequency. You should also use your eq to pump these missing frequencies if they are coming in too low.
2. Do not mud up your song by putting to many sounds of the same frequency range this will not produce a desirable effect, keep your song clean sounding. Take an overview of your song and what you are using to fill these specific frequency ranges. Get rid of any sounds that are causing complications in the mix they will only make it sound worse.
3. Clearly label all of your sounds, FX, and anything that you can about the song you are writing because chances are you'll eventually come back to it without a clue of where you left off. If you work on one song at a time sticky notes and/or masking tape for your mixer and monitor will do the trick quite nicely.
4. Save your song as new versions, as it progresses, so that if it starts sounding worse than the previous work you can go back to its basic structure and re-write it.
5. Hearing the same riffs over and over can start to numb your ears of its catchy sound. Go back to what you are working on after a nights sleep its always better to have a listen with fresh ears.
6. Keep the volume at a reasonable level while you are working in your studio and only turn it up once and a while. This will help yourself from going deaf and will help maintain your interest in the song while you are producing it.
7. I have said it before and I will say it again, save a back up file of your work, hard drives randomly crash without warning, it's better to sort through a bunch of files on CDs than to loose your song.
8. Experiment as much as you can, as long as you have back-ups you can always go back. Producing music is all about stretching the boundaries outside of the mainstream.
9. Keep all of your files in order sometimes this can help when going into the songs final mix down. and really helps when backing up all of your songs rough work for any future re mixes to come.
10. Continue to produce lots of music, you will always learn something after writing every song. Its all about finding that one good sample/sound that catches your ears attention, and sticks in your head for the rest of the day.