When writing, one should always start sentences with a capital W. "Why?", one might ask. Well, I'll tell you. Where the sentence begins, is where we direct the reader's attention. We want the reader to look forward to the next thing. "What is he going to write next?"
A different letter - is the answer. Because there are others words than those beginning with W, that can direct the attention to the future and the unknown. Could you see yourself, telling your reader to stop focusing on what you wrote?
The text should be the focus of your something yet to be discovered.
Look at the above sentence again carefully, and notice how every word alludes to the next one, without creating a complete sentence, until you reach the last word (in this case "discovered").
These are all words which are good to use at the beginning of a sentence.
I'm a good writer and so can you.