That is a pretty open-ended/vague question, care to narrow it down or define it a bit? Are you looking to secure your tent(s) from wild animals? From humans? From theft? Are you interested in general camp security? Security while in camp or away from camp? From the wind? Campground or remote?
Away from camp - don't leave expensive/cool stuff visible to humans. Leave a person in camp. Don't venture far from base camp. Go remote, really really remote. Leave music on at a low volume or some other "signs of life". No guarantees, humans will be humans.
In camp - firearm(s); caliber on hand depends upon the assumed threat. Something big in bear (or spammer) country, something smaller in human country.