Be yourself, that's what I'd say. When I began I tried to sound more professional, and I didn't get as many views. After I took a break and decided to be myself, more people started noticing my channel. You will look a lot more comfortable on screen as you are not trying to force anything. From there on in, if you look at your videos and feel you need to change something, then adjust as necessary! I think having a balance is important, so try to maintain that, but make sure you are acting in the theme of your channel, and that you aren't trying to be someone else!