At an ambulatory clinic where I once worked, we had one really cool manager who would very quietly compliment or praise us individually on something at least every other day. No big announcements; she would just walk through, look around, and as I'd be charting she'd lean over and say - quietly - "hey - that was really nice of you to wipe down that patient's wheelchair without being asked. Very cool - thanks so much." Or, "I noticed you've been the one signing off on the CNAs crash cart inventory all week - thanks so much for helping out. I'll make sure Jane does it next week so you get a break." Those little compliments for little things were REALLY nice, and I always made a mental note to do the same if I was ever a manager.
She would also spontaneously treat the entire unit to coffees, and I mean she'd get everyone's complicated Starbucks order, whatever we wanted, and when she came back lugging all the cups she'd give us 10 or 15 minutes to enjoy and chat. She'd do that every couple of weeks and tell us it was a thank-you for our hard work. Small but nice - and I think it came out of her own pocket.
ANONYMOUS ways to suggest changes are good;
And maybe a once-or-twice a year volunteering day where we helped at a blood drive or free immunization clinic or something in the community, earned us a paid day off which was good incentive! And, it was seriously fun. We volunteered at the blood drive from 10AM-4PM then went out for drinks and food after.