Buying your tickets...for some festivals like Glastonbury ticket buying is beyond complicated and you have to buy before you know who is headlining, for smaller festivals ticket buying is usually easy. And some festivals let you pay weekly to spread the cost. Camp Bestival and Bestival both do weekly scheme.
Why not start preparing ... do you have a tent? well now is the time to check it, with 74 days to go there's lots of time to sort out anything that needs doing. I pitched mine and found some of the rubber bands that secure it had perished and needed replacing. I was missing a guy rope (how that went missing while the tent was in storage is anyone's guess) and I seem to have misplaced my duct tape!
So get it out (!) erect it (!) and see if you need any new rubbers (!) etc
And if you have no tent there is time to look around. Check out some of the things to think about on my tent buying advice post.