It's always good to establish yourself in a topic. However, sometimes it's good to be spontaneous as well.
Jump in and do something you don't usually do to give your readers something different. When you fall into your typical pattern, it may appear to your readers that your main habit (or group of habits) is all you know.
Being spontaneous with your writing helps readers get to know you, keeps them interested in coming back for more, shows clients and potential clients what you're capable of, and also may bring in new readers who may not have noticed you otherwise. Plus, it's good for you as well. Spontaneity can help develop writing skills you may not have exercised before.
Have you ever been spontaneous in your writing?