I second the buffer and the drawing big>resizing thing! Both great things to keep in mind! You don't need to be as crazy as I am with your buffer (yes hi I am 50+ pages ahead of my readers), but having a big buffer is a big help.
I'd like to add these:
1.) Plan ahead
One of the worst feelings in the world is opening a new document, or placing a fresh, empty sheet of paper on your drawing table, and not knowing what to draw on it. Planning ahead - by outlining, or by doing thumbnails or by whatever method you choose - is a good idea, because it means you lessen the risk of staring at that empty page and drawing a complete blank. Know what happens next, and your future self will thank you for it.
2.) Don't be scared to challenge yourself
Don't let the feeling of "I don't know how to draw this" limit you. If you want something to happen in your comic, and you don't know how to draw it, do it anyway. Experiment! If you fail, you will still have learned something!
3.) Expect failure
You're going to fail. You're going to mess something up. You're going to make mistakes. You might mess up your updating schedule, you might make spelling-mistakes left, right and center, you might draw your characters wrong - accidentally drawing their nose crooked, or their hair parted the wrong way, or get your characters' expressions wrong. Inevitably, people are going to notice.
This is okay. This is fine. All you need to do is look at your mistakes, correct them if you can, and resolve to do better in the future. As long as the people pointing out your mistakes aren't being vicious about it, thank them for pointing it out and move on. If they are being vicious, try your best to ignore it.
4.) Be patient
Comics take a long time to make, and it takes even longer to find an audience. Nobody is an overnight success - you just have to keep plugging away, keep working on making better comics, keep putting your work out there to be seen, and eventually your comic will start gaining a readership.
But you are going to need to be in this for the long haul.