Seiyuu blogs have a number of common subjects. Food is the most common: sushi, curry, desserts, coffee, beer, cookies, etc., etc.
Of course, publicizing new work is the whole point of the exercise, so that's there, too. But trips to the hairdresser, and new outfits also loom large.
However, a very common subject for blog posts is new nails.
Seiyuu often seem to be showing us photos of their new nails. Search Google images for ネイル (the Japanese for "nails") and you'll see many different styles. Or check this blog of a Japanese nail salon that has served at least one seiyuu.
Just today, Koshimizu Ami (below, left) and Sanpei Yuuko both posted pics of their new nails. Now, tell me they don't live together, lol. At least they help each other figure out how to keep up the posting rate on their blogs. Ami says she made one finger brown like the chocolate Japanese girls give on Valentine's Day. I like Yuuko's shorter nails.
Anyway, here is a wall of images of the nails of various seiyuu that I happen to have found in their blogs. Mouseover to find out whose nails are whose: