hi there anon,
working through tutorials is probably about the best thing you can do. as well as a lot of googling and research – you should probably also bookmark the following sites as they’ll be a LOT of help –tumblr custom theme docs
w3 schoolsi’ve written a small series that will walk you through making a theme – as well as other coding tips over on my ‘tutorials’ page.
G D O E S A T H I N G – HOW TO MAKE A TUMBLR THEME FROM SCRATCH;
- theme 101 part 1 – basic html, styling body, styling and positioning posts
- theme 101 part 2 – the padding function, the margin function, permalinks, tags and styling
- theme 101 part 3 – styling general links, styling bold and italic, styling blockquotes, images
- theme 101 part 4 – styling sidebar, navigation links, headings and pagination
- theme 101 part 5 – index and permalink pages, float, post info, styling asks and quotes.
- theme 101 part 6 – adding images, backgrounds, sidebar graphics, etc.
- theme 101 part 7 – container theme, scrollbar, overflow, hover effects.
[ parts 6 & 7 come with full BASE CODES… ]
other theme makers have also published tutorial series, so i’d also recommend you check out;
then just change things, learn as you go – and mostly – have fun!