Clean Inbox ～ We Sort.

Clean Inbox or Inbox Zero is an approach that aims to minimise distraction and stress. The premise is the same as using a traditional paper inbox: it should be empty at the end of each day. Obviously, this is an ideal and in practical terms rarely achieved.

Principles

The only messages that should be in your inbox are ones that require action (read, reply, task – though a task management system is better suited to the latter)
Archive (or file) messages out of your inbox when you are done with them. Delete only emails you won’t need again (promotional email, feedback surveys, etc) – never delete correspondence.
Use search to find emails that have been archived. Folders and labels take effort to maintain and are only useful in a few contexts.
Ensure the subject line is applicable. Long running email conversations or threads can be very confusing - especially with multiple recipients. Set a clear subject, and create a new email with a more appropriate subject line if the content strays.
Write emails that don’t invite unnecessary further emails. Be specific with questions, options and time frames.
Prioritise older messages. Along with the count of messages in your inbox, the age of messages is important too.
Personally, I feel responding within 2 working days is acceptable – however your sector may differ. If someone needs you faster, they should have your phone number so they can call you.
Discuss topics verbally, confirm what was discussed by email. Email is great as a written and asynchronous record, but sometimes meetings or phone calls are far more effective.
Unsubscribe from mailing lists or newsletters that you never read.
Turn off audible notifications for email on your phone.

Gmail is especially suited to a clean inbox

A user’s mailbox is essentially one big pile of mail, and labels function like filters so individual messages can exist in multiple locations at once.
The inbox is simply a label applied to all new messages as they come in. Archiving a message removes the “inbox” label.
Turn on Send & Archive under settings to clean messages out of your inbox when you reply to someone.
Advanced search has a lot of power if you’re having struggling to find something.
Snooze messages that you’d like to return to your inbox at a specific date and time.

Disposable addresses

If you have a catch-all address setup for your domain, you can create ad-hoc addresses.
Setting up a catch-all (in Google Workspace Admin or whatever email provider you use) means anything in front of the @ symbol of your domain will still be delivered to wherever you set that up for.
I use this sometimes for recipient-specific email addresses when filling in sign-up or marketing forms.
For example, if I was signing up with a company called Acme on 22 March 2023, I could give my email address as acme-2023-03-22@wesort.co.uk and it would still come to me.
By doing this you don’t reveal your primary address, enables you to filter out or delete messages to this address, and provides proof if it’s used or shared elsewhere unexpectedly.