Lyric writing can as is seen as the hardest part of songwriting.
Thee job can be made easier by breaking it down into several parts.
First come up with an intention.
1. What kind of song is it?
2. Person narrative ...First (I) , Second(You), Third (They)
3. Where is the narrative based?
4. What happens in this narrative.
This is usually where people start, they think of a line and try to end the last word of corresponding lines.
Starting with the lyric is a great way of writing you will need to find the meter and rhythm of the lyric and build the song up from there
Try using a rhythm first, and use this to fit the internal rhythm of the lyric on and around, you will probably need to change the phrasing of the words, or the words themselves.
Some lyrical devices