What's one productivity hack that you want to gatekeep?

I'll start, I can't believe I didn't know this -

A friend taught me earlier today regarding the "plus trick", also known as "plus addressing", for Gmail addresses.

You simply type in + after the prefix of your email address along with any text, and any email sent to this will still arrive in your inbox.

For example: If my email is sean@gmail.com, any emails sent to sean+business@gmail.com, sean+product@gmail.com, will still arrive in the inbox of sean@gmail.com.

It works because Gmail internally ignores + and any text that comes after it. Try it out.

Since I've shared mine, now I'm going to peer pressure you into sharing yours. Go!