Surprisingly enough, not too many people are aware this feature even exists, and it's by far the best thing about the already wonderful Gmail service.
Create a Gmail account and you automagically get unlimited variations of that address as such that it very much begs for some order / classification. You had several mail accounts like I did? One for spam, one for family, one for customers and what not. Then Google gave you the chance to link accounts and of course we've always the ability to forward emails. Yet non gives you the sheer flexibility of a fine grained email address.
The only downside really is that not every website form may allow for all of these addresses, then you might need to play a bit with the dots...
Step 1: Create a Gmail account
Step 2: Try out your unlimited emails
Use a different email account or just your own Gmail and mail yourself ^^ If you created email@example.com consider the following illustrations, all of these are already yours:
firstname.lastname@example.org email@example.com firstname.lastname@example.org email@example.com
All of these email addresses should resolve back to the original:
You could make tags for potential spam and filter them based on the email recipient pattern '*+spam', you can create levels by numbering 1,2,3 in some kind of grade system you might use, have contextual auto-reply etc :)