For me I usually look at my subscribed threads under 'settings', then locate the Falmer Webcam, but generally if I just browse the Big Board I do not look much further than the first page.
I normally click on I'm Feeling Lucky first, to see where it's best to begin. Every now and again you find yourself in a time when only bensgrandad existed and on other occasions you're locked in the darkly amusing teen years of Beach Hut discovering the reasons for his hatred of geese and the semi-romantic beginnings of his love-hate relationship with Ernest.
I have so little life and am on here so frequently, that my unread threads rarely go beyond half way down the second page, though since I usually only look at threads that seem as if they might be interesting, it doesn't take long to check through them.
I open to forum page, click "New Posts", read what want I want, then return to main page and click "Mark Forums Read". This seems like a good way to pick and choose.