There are some strategies and techniques for dealing with this. First, keep in mind when writing a song that the first thing you write does not have to end up being the first verse. Often times, when a first draft of a song is done, the second verse winds up working better as a first verse, and the original first verse might get tossed or re-worked into a different place in the song.
The most important factor in determining this is the flow of information to the listener. If your song is telling a story, consider how you would relate this tale to someone if you were lust telling it to them in normal conversation. Forget about lyrics and melody and meter. Just tell the story, and look at how the flow of information unfolds.
What background do you need to give about the people involved? Do you need to convey where this happens, or when? How will you let the listener know what the situation is, what the conflict is, why it happened, and why this is relevant?
To help organize this flow of information from a conversation into a song, try the "Box" technique, used by screenwriters, playwrites, novelists, and songwriters alike. Draw some boxes, representing the sections of your song. For example:
Without worrying about actual lyrics, just ask yourself what information needs to be conveyed to the listener in that section, before getting to the next section, concentrating primarily on the verses first. Then you can see whether or not you need a bridge. A bridge is always optional.
The chorus in general is going to be a summarization of what the whole song is about, rather than moving the story along. Notice that the chorus box is shown as being larger each time. Why is this ? It's not because the chorus gets longer each time – the chorus is generally going to stay the same with each repetition. If it is working well with the verses, the chorus should gain weight and become more important each time it is repeated. Thus the increasing size represents significance, not length.
When you have established what information needs to go in each section, then you can start looking line by line within that section to see how you're going to get that information across in the number of lines you've allowed for yourself.
A song does not have to have all these sections or follow this exact structure. If you can say everything you need to in just 2 verses, don't write a third. The important principles are:
n Think in terms of information first, not just lines.
n All the verses should share a common structure
n The chorus should logically flow from the verses
n There is never a need to repeat what has already been said (except in a list song)
n A bridge is optional and usually occurs only once
n Get as much of the 6 W's (who, what where, when, why, how) into the first verse/chorus as possible
n Make sure all the necessary information is presented in a logical order
When you have an inspiration for a song, and quickly get a first verse/chorus written, that a good time to stop and think it through in terms of what you're really trying to say, and how you're going to say it. Just talk it through as though you're telling a friend in normal conversation, and listen to the flow of information.
One final consideration: It is also important to remain aware of the structural issues as you develop a song. Once you decide which verse is actually "done" (it does not have to be the first verse to be the first one that's considered finished), that sets the overall line-structure, meter, melody, and rhyme scheme. Each of the other verses should then try to fit as closely as possible to that structure to maximize the overall consistency and thus, memorability (stickiness) of the song.