Learning songs from your favourite artists is a joy for any level of player, but there is nothing that compares to writing your own. Many people I have taught, from complete beginners to accomplished artists, have sought to discover some mysterious 'secret' to songwriting. But there is no real secret to writing a great song, or even one essential formula for success.
And songwriting doesn't even have to require a vast amount of theoretical knowledge - some of the best writers have put together hits with a very limited understanding of music theory. It all depends on the style you want to play and how you want to express your creativity.
But that said, when you know your craft it becomes so much easier to capture the moment when it arrives. And it really doesn't take much to get started - I've had people producing albums-worth of material after only a couple of lessons on writing theory - and the discovery of new knowledge and new techniques can sometimes be just the inspiration you need.
Here are some of the areas covered: