1. Go find an old music magazine and read a review of a band / record you have never heard before. The review can be positive or negative, doesn’t matter (sometimes nega- tive is better). Fanzines work too, especially old local ones that have articles about bands that existed for five minutes or something. Anyway, get your guitar and write a song that sounds like what you imagine the unheard band / record sounds like, based solely on the description in the review. Chances are very good that if and when you do hear the actual band / record someday, it will sound nothing at all like what you wrote.
2. Put a capo on a random fret. Start strumming a C chord and free associate until a melody inevitably comes. The capo will allow you to play in familiar first position shapes, but you’ll be writing using chords you’d probably never dream of using, unless you’re a jazz genius or something.
3. Talk to grandma. She probably uses words and expressions people rarely say these days, like “Goodnight, nurse!” and “How do you like them apples?” These can be great titles, or lines in a song you can play with, modulate, modify, bend to your will. These expressions usually vary regionally, too, which is neat. If your grandparents are dead, old movies and tv shows from the forties and fifties will work, too.
4. Steal. Pick a popular opening line--”Here I stand, head in hand,” “How many roads must a man walk down?,” “How old are you now?”--and sing it over some strummed chords. But don’t sing the melody of the original song - sing your own melody. Then go back and change the words. The power is in the syllables.
5. Keep your antenna up. Anyone can write a song, but the thing that separates you from the people in line at the bank or the grocery store is that you know a good title or a good first line when you hear it - most people ignore these things. Unless you live on Walden Pond, these things are everywhere. In fact, it is almost impossible to ignore the soundscape that is modern life. Find in these soundscapes the expressions, mixed metaphors, potential puns, and mistranslations others take for granted and use them. Songs are everywhere. You just need to recognize them when you hear them.
6. Never, never, never sit down with a blank sheet of paper with the intention of writing lyrics on command. I have heard of songwriters who claim that this technique works- -they will claim to be on some sort of regiment, setting alarm clocks and “working” for a predetermined amount of time, as if “on the clock”--but I don’t believe these people are being truthful. I’d wager that the best songs these people write are not during this tedious-sounding ‘work time,’ but at stoplights, or while lying in bed unable to sleep, or showering, or cooking. I do not doubt that the ‘blank sheet of paper’ (or, if you like, blank Word document) approach can produce a song, only that it can produce a great one. You don’t create great songs from thin air, you steal them from the sky. Remember: you are a medium - not a machine.
7. Switch to keys (or, if you play keys, switch to guitar). Not knowing how to play keys should not stop you; it may even help. There’s a terrible David Crosby and Graham Nash song about this--they advise to just play the black keys, and you will suddenly find yourself writing a song. I have found this to be true.
8. Borrow an instrument from someone who plays the same one that you do. Renting works, too. Every instrument has a finite number of songs living inside of it, waiting to come out like some cocooned creature. The reason some songwriters hang onto one guitar for their entire careers is because they get lucky and find a very generous guitar. Some guitars are stingy and don’t like to give you songs. If I had billions of dollars, I would buy a new guitar every day, giving away the one from the previous day, and I would write millions of songs. This is also why instruments should never be smashed or burned or otherwise destroyed, aside from that tired practice being an aristocratic and lamely showbizzy thing to do: because it is literally an abortion of the incubating songs unique to that instrument. Anyway, back to songwriting. This trick works great if you have a friend who also writes songs. Lend him your guitar and borrow his. Then meet up in a week and play all your new songs for each other. I bet there’s a ton. A new (or new-to-you) guitar will give you new songs - I promise.
If none of these tricks work for you, it is possible you are not meant to be a songwriter. You may have written some songs, but you may lack the mutation that songwriters have that allows - or rather, compels - them to do what they do. You should learn to play bass. The world needs great bass players more than it needs songwriters, and bands, while rarely on the hunt for songwriters, are always looking for bassists. Cellists also seem to get a lot of work for some reason. Good luck.