Write just as much as you can as often as possible, and try different topics, rhyming schemes, backgrounds, and techniques. It takes time to perfect your look. Be pleased with whatever you write, but acknowledge that the longer you perform it, the better you’ll get. Never throw away your older pieces, though. You may be able to revisit them if you are more experienced and possibly rework them or reuse elements of them, like the background or elements of the lyrics.