Dont spam!
Maybe link to several websites, so its not too obvious. Domain age also is something some mods look for.
Have a girl username, less ban-rate.
Listen what people say on the forums.

It can be great but it can also be spammy and that’s not that good. So its good to not over do it and link to very appropriate stuff. I try to do it in a very small scale I have never actually done it in a bigger scale.