Lyric-writing is a craft as well as an art - words have more or less power and meaning depending on the order and context in which they are conveyed, and knowing some tricks to getting the maximum impact (and least amount of song self-destruction) from your lyrics should really be of high priority. Of course, there are no "rules" in writing, but there are observable effects on the listener depending on how you construct the lyric, and you can simply choose to use these tools or not.
Here's my three worst contenders for shooting yourself in the lyrical foot.
1) Don't use perfect rhymes
This is probably the most amateur mistake of all.
Try to use other types of rhymes instead - eg family rhymes, internal rhyme, additive, subtractive, assonance or consonance rhymes.
Although a part of our brain always desires perfect rhyme, we have come a long way since the early days of songwriting, and all those obvious perfect rhymes have been so well-used that they are now totally cliched and too-predictable.
Get yourself a rhyming dictionary (there are online versions too, although I prefer the MasterWriter app) and choose rhymes that are less obvious and maybe pleasantly surprising. Instead of using the perfect rhyme "Bread" and "Head", maybe use a family rhyme - eg "Bread" and "Web" or "Tear". In singing, we generally tend to rhyme vowel sounds, and the consonants matter less. Check out books/articles/workshops by lyric guru Pat Pattison for more details on rhyme types.
Note that sung rhymes are not usually the same as written rhymes, so make sure you sing them as you write to make sure that they ARE singable.
2) Use "spotlighting" effectively
There are natural accents within a musical bar that will automatically highlight or spotlight to the listener any word or syllable placed upon it. These spotlights tend to be on the downbeats of the bar, plus a big one at the end of a line, and even bigger at the end of a verse.
Ignorance of this behaviour means that you may end up with "nothing" words like "the", "and" or "but" placed on these prize positions in the bar rather than your cool meaningful words.
This risks weakening your lyric and can even undermine the meaning of it by placing importance on the wrong word.
Back in 2007 I wrote a song, just before going to a Pat Pattison workshop, that included this lyric:
"The tide is slowly rising, Blood red sun on the horizon"
Spotlighting these words:
Tide, slow, rise, bloodred, sun, the, horizon.
Notice how "the" has a spotlight that it really doesn't deserve?
I fixed it in this example by removing it from the spotlighted position:
"The tide is slowly rising, Blood red sun on ....the horizon"
Here's the link if you want to listen (warning - ultra-demo quality!): Tied up in Knots
Note also that "rising" and "horizon" rhyme when sung.
And in relation to syllable position:
3) Don't put the "emPHAsis on the wrong sylLAble"*.
As much as possible, try to sing as you would normally speak in conversation. If you don't, you risk breaking the meaning of what you are trying to get across, and it can sound contrived, amateurish, or just like you haven't taken the time to make the lyric fit the music properly.
You should be able to read your song lyrics out, spoken-word fashion, and the phrasing shouldn't be too far away from how you sing it. Or vice-versa. This is most noticeable when you're going for an "authentic"-style delivery (rock/blues/indie) rather than stylised (r'n'b, soul, pop) - accenting the wrong syllable can instantly break authenticity. The listener will go "huh?" and the flow and belief is broken.
There are many more lyrical tips than this, of course, and some equally or more important, but the best idea is to do a proper workshop or short course on it, or at least get a decent book or two about how to structure your lyrics.
For those of you who balk at being told what to do - I remind you that these are not rules as such - they are simply based on observable effects on a listener, and you can still go ahead and do whatever you want.
Sometimes you might need to make a call between including a word that adds the perfect meaning to your lyric, and having to jam it in there a bit more clunkily since it doesn't quite fit. But you should definitely be aware of the risks on how the listener will receive and decode your meaning when you decide to do things like this.
And finally - you should ALWAYS use some kind of rhyming dictionary - otherwise you are relying on a choice of only the rhymes that you can currently remember. Which is often only a small fraction of the huge amount of available rhymes - many of which are probably more interesting than the one you can currently think of.
*As spoken by Mike Myers in "A View From the Top".
Pat Pattison: Essential Guide to Rhyming (Formerly titled Rhyming Techniques and Strategies) Berklee Press, distributed by Hal Leonard January, 1992
You can order all these three books - Writing Better Lyrics (second edition), Essential Guide to Rhyming and Essential Guide to Lyric Form and Structure for a special price here
Jason Blume: Writing Hit Lyrics with Jason Blume - get the book here