Short and simple is always great but this is the part where you need to spend one and the most amount of time because if your email does not open it's not going to get read. It has to be either eye-catching, create urgency, connect to ask a question, make somebody intrigued and peek to do that. You never know what's going to work some of my subject lines that I'm like oh it’s going to get open right now it doesn't work and then he had one email that opened in an incredible way.