Shaddows - 12:49 pm on Jul 30, 2010 (gmt 0)
I simply started with the titlebars and ensured they were even more accurate than ever, meta keywords, yep I still do those, meta descriptions, changed the h1 and h3 to ensure it matched the titlebar, made sure all images had completed alt and title information, added synonyms where applicable, I also put these in the meta keywords, plus extra technical descriptions which were also reflected in the meta description.
And that got you a boost? Very interesting.
A year ago, sitewide tinkering in such sensitive areas would have earned you a series of page-penalties (-30 or -60 usually), with the strong possibility of a sitewide -50 depending on other 'suspicious' criteria (link related).
If you avoided that, the dreaded -950 OOP (everyone forgotten about that?) would be just around the corner.
Maybe Caffeine and 'orthogonal'* algo changes have ended the era of penalties-for-penalties-sake, when Google shot first and asked questions later (usually exactly 90 days later).
*apologies for borrowing MC's terminology, but it's a good word. Better than [simultaneous, concurrent, related, independant, contemporary]