I want to give you a tip on how your profile links are not immediately deleted by the admins of any forum!
Do you know that? You create profiles for hours on high PR forums / communities such as .edu and .gov forums! And after a day or two you notice that your account has been deleted to the forum. And the URL to your profile is no longer available! Your account has been deleted because it was too obvious that you were just on backlink hunting.
My trick: While creating a profile on an edu-page , I initially put a link to a topic-relevant university page of my country!
For example: If I register an account on a site with the topic "geology" (something like: forum.geology.site.edu /register /etc ...), then I look for a geology page at a German University (https*://portal.uni-freiburg.de/geologie..) and I put this link in the field "Website". In the field "Occupation" I put something like "post doc at the geological departement Universität Freiburg bla bla... When the moderators check the list of new members at the next morning, you can be sure that your profiles are not considered as spam!
Then I wait a few weeks until I'm outside the list of new members. If my profile is disappeared between all the other profiles, then I start to place my proper links.
I've tried this already a few times, and so far it has always worked really well!
What is your strategy to avoid deleting your profile?