So all these tasks I create in my to-do list can have tags... why would I want to tag my tasks? What tags should I use?

Tags let you organize your tasks however you want to.

Have a tag for each of your projects

Use tags to group together all the tasks you need to do to complete a certain project:

Send invites; Phone DJ; Get first dress fitting... all get tagged with "wedding"
Phone Mum to get Aunt Hilda's address; Write thank you letter; Post letter... are all tagged with "ThankYouLetter"
Get sales figures for March; Arrange meeting with Bob to discuss problem areas; Write slide deck... get tagged with "SalesPresentation"

Then you can easily see what remains for each project just by looking at all the tasks tagged with that tag.

Tag tasks based on where you need to do them

If all the phonecalls you need to make are tagged with "phone" then you can pull up the list when you've got the phone and then blitz through them all at once.

About to head into town, or to visit your parents? Check the "town" or "parents" tag to make sure you haven't forgotten any errands you need to run, or things you must remember to take with you.

Tasks that need somebody else's input can be tagged with their name

As you come across things you need to discuss with your boss, Jack, just add them to your list and tag them with "Jack". Then when you get together for your weekly one-on-one you've got a ready made list of issues to run through.

Tag to stop yourself being distracted

I have a "focus" tag which I use to mark any task I want to get done in the next couple of days. Then once or twice a week run through the list of all my tasks, and check that the right ones are on the focus list and add or remove the focus tag as necessary. So most of the time I'm just looking at the list of tasks tagged with "focus", and my to-do list isn't cluttered up with everything else.

Tags let you mix and match

And the real bonus of tags rather than projects, or contexts or priority levels is that they're flexible enough to be all of those things. All at once.