A lot of times, I've worked with artists and they've experienced writer's block. And they always try to figure out, how do I figure out a topic to write about? So, one way to start a topic is to just write about what's on your mind at the present time. Many people try to find topics by listening to the radio or seeing what somebody else is doing, but that's actually the incorrect way to try to figure out what you want to rap about.
The best way to create a topic to write about is really journaling. Just write about whatever's on your mind, whatever's going on in your personal world. And, out of that, you can extract a portion of that and speak on the topic.
For instance, if you may be going through a breakup in a relationship, you might write about that. And when you journal about it, you make look and see that you have an actual story or content, and so you take that content and then you turn that content into a song.
Another way may be just to turn on the television. You may see something that's going on in the Gaza Strip or that may be going on in Brooklyn or in Oklahoma, and you can give your perspective on that particular topic.
Another way is just to write to somebody. A very popular song by a rapper called Nas is called "Illmatic". It was a letter to his friend, who was in jail. And that became one of the most popular songs of that year in which he wrote it.
So, the key is to look in your own life. Make it either personal, a perspective that you see on something going on in the world, or write directly to somebody. And those are three easy ways that you can come up with a topic to write about.