The D5600 is already fairly efficient, so the biggest practical solution is still to carry one or more spare batteries. But you can stretch each charge by reducing the camera features that use the most power:

• Use the optical viewfinder instead of Live View whenever possible.
• Limit rear LCD use: turn off automatic image review, review photos less often, and lower LCD brightness if needed.
• Reduce flash use; it draws a lot of power.
• Let the camera sleep sooner when idle.
• Avoid continuous AF/tracking unless you really need it, since repeated focusing uses power.
• If practical, use manual focus or back-button focus so the lens isn’t refocusing every half-press.
• Turn off high-speed continuous shooting or extra multi-exposure features when not needed.

In general, trying to squeeze a huge number of extra shots from one battery is less effective than carrying charged spares, but these habits can noticeably improve battery life over a long day.