Writing your own jokes, you just kind of keep working on something until you think it might work, and then you try it out and hope for the best.

This quote is referring to the process of writing jokes. It means that in order to write jokes, you must first put in the effort to figure out and create suitable material. After that, you must take a chance and try out the joke, and hope that it is funny or successful. In other words, you can only tell if a joke was successful by giving it a go and seeing how people react to it.