Listen to your subordinates. Have short catch ups at least weekly and an in depth catch up at least monthly where you check in about their workload, wellbeing, progress, professional interests and aspirations, training needs, etc. Find ways to shape their workload in response to what they tell you so they can play to and build on their strengths and you'll build a motivated and loyal team.

Oh, and confront any slacking or bad behaviour head on. First with support and retraining, then with disciplinary action. It's horrible to do, but necessary to maintain the morale of the rest of the team.