Most monitoring projects fail the same way: the team installs the monitoring tool, enables every default alert, gets paged 47 times in the first week, and turns off Slack notifications for the monitoring channel. By month two, nobody looks at the dashboard. By month six, the monitoring tool is the most expensive screen-saver in the office. The failure isn't technical. It's that the monitoring was tuned for the maximum possible coverage, not for the alerts that actually require human attention.
Good monitoring inverts the default. You start by asking: what are the three things that, if broken, would actually require somebody to do something in the next hour? For most small businesses, the answer is something like: the website is down, payments aren't processing, or email isn't sending. Those three things get pager-grade alerts — phone notifications, escalation paths, the works. Everything else — CPU usage trending up, disk filling slowly, a single 500 error — gets a dashboard view that somebody looks at during their morning routine, not a page at 3 AM.
The second principle: every alert must be actionable. "Server load is high" is not an alert; it's a metric. "Server load has been above 80% for 15 minutes and response times are exceeding 2s" is closer to an alert, but it's still missing the action. The most useful alert template we know is: <symptom> + <impact> + <suggested first action>. When the on-call person's phone goes off, they should already know what the first thirty seconds of their response looks like.
Finally — and this is the principle most teams skip — alerts that fire and turn out not to require action should be tuned, downgraded, or deleted. Every false positive trains the team to trust the system less. After three weeks of "oh, that one fires sometimes but it's nothing," the team will sleep through the real one. Monitoring is a living system: every alert you don't tune is an alert you're slowly teaching yourself to ignore.