I am BGG's official honey trap
Go to particular game in database, and look for Fourms section. One of the forums is Sessions.
Yup so select 'post' then pick which forum 'session reports' then write your post.
Session reports are automatically modded - which means 3 people will vote on whether your post will be accepted.
You will then be informed via geekmail and may be rewarded geek gold. This process can take around an hour in my experience.
I'd make sure you save your own copy of your session report just in case.