1. After some probation period, fire only as a last resort or for really terrible behaviour. Have a plan to correct behavior in all other cases.
2. No layoffs unless the firm's very existence is threatened. It's a tough year? Too bad, that's part of the risk involved in being the owner.
3. Keep pay up to market/replacement rates. If someone is 20% more valuable with his new knowledge, pay him 20% more. 4. Have good benefits/vacation policies.
5. Make sure there's lots of interesting and challenging work to do. Allow people to switch roles/teams on a regular basis if they're interested.
6. Hire good people.
That's a company I'd be loyal to, and I think a lot of others would be too. Sure, you'd get people who would leave for their own thing, or a dream job, or because their husband/wife got a job 2000 miles away, but I don't think you'd see people jump ship nearly as often.
The other stupid thing is companies trot out how much it costs to hire a new person, but never want to invest in just retaining their employees.
You'll often find places like this away from the big hubs. They're doing "quite nicely, thank you" with no ambition to become #1, IPO or make the owners richer than Croesus. They also tend to have little to no problem recruiting good people in their 30s and 40s into their nice part of the world where there are good schools, affordable homes and comfortable living.
Nowhere is perfect, the grass is always greener etc. You couldn't pay me enough money to move to London from Scotland.