How do I write a good post?

You try to achieve few things:
promote yourself by having something interesting to say
reference and make friends with others, they might be likely to promote you in the future e.g. (e.g. @UkiDLucas)
promote event, or review URL (e.g.,
promote event #hashtag so people can find more posts about the topic
write posts in about 120 characters; leave about 20 characters so people can quote (re-tweet) your post without shortening it

Uki's Google Java Technology blog