IMPORTANT: Please please please do not distribute/copy any tutorials found here to any other tumblr sites. I have spent a very very long time making this for you and it would literally break my heart to see it's content splashed over any other tutorial blog. I know you wouldn't do that anyway, 'cos you're beauts. Please note that if you do decide to copy my tutorials you will be reported, there's not excuse for laziness.
Before you even attempt to make a theme, you should be fluent with html/css. Html and css are different. If you need help remembering a code or whatever, here is an amazing website with pretty much every css and html code you’ll ever need to design your theme.