Creativity and getting original ideas is one of those things that can both be coaxed with applied effort yet can also be even more elusive if you're forcing it.
There's a lot to be said for sitting down and just going for it, writing or composing anything that comes to mind until you get something good. Some people say just do it and don't censor the ideas until later upon review, and this is the best way to get the creative juices flowing. It's important not to self-judge everything that's coming out while it's coming out of you. For writing, for example, just start writing anything and see where it takes you. Music composition, the same, just start playing some notes randomly. Then play them over again and see if they suggest the next few notes. Just be playful with it and be prepared not to think it's any good, just let stuff happen.
With songwriting, you don't really need an interesting life, especially -- you can think about emotions you've felt, and write a song about that. Most songs are about emotional life, feeling happy, feeling sad. You don't have to specify what you feel happy or sad about -- art can be left mysterious and nobody minds too much.
The other side of all this is that if you have to force anything, it usually proves more difficult; creativity can respond to applied coaxing where you get into a relaxed space, but it dies when forced due to a feeling of pressure and frustration and too much efforting to create.