Keeping data clean.
WHY IT MATTERS
On a small site, your own visits can be a large proportion of the total.
That distorts everything.
WHO TO EXCLUDE
Yourself Your staff Your developer Anyone working on the site
HOW
Most analytics services offer address-based exclusion, or a browser setting.
Set it up immediately after installing.
THE CHANGING ADDRESS PROBLEM
If your address changes, exclusion by address stops working.
Check periodically.
FOR MOBILE
Your own phone visits count too. Exclude those as well.
HOW TO CHECK IT WORKS
Visit your site, then check whether the visit was recorded.
It should not be.
WHAT ELSE DISTORTS DATA
Automated monitoring services checking your site Uptime checkers
Those appear as traffic. Exclude them if they are significant.
WHAT TO DO IF YOU DID NOT EXCLUDE YOURSELF
Historic data is distorted. Note that when comparing periods.