Official Gmail Blog: 2 hidden ways to get more from your Gmail address
I just found on the GMail Blog two neat features you can do with your gmail addresss. One I've known about for years, and that is using a period in your email address. so firstname.lastname@example.org is the same as email@example.com, and you can use that to figure out where spam is coming from, if you place the period in different places of your email. That's of limited use, unless you want to be spiffy any have a period separating words in the email address. The other item that I didn't know about and was really interesting was using the + in your email. So you can send email to firstname.lastname@example.org. Then create a filter for the +orders and have all your orders labeled. I've started using +spam, +orders, etc. I then know if someone starts to sell my email address to other companies, I can just start blocking the +.
I use this with my google domain email, and it works great!