Not many things can go wrong on Switch level, but issues are also difficult to troubleshoot there.
L3 Switching and Redundancy: VLANs and Routing will be the main section to check for issues on L3 switches(maybe L2 also)
Switch#debug terse <- Only show the debug message except HELLO message
Switch#show spanning-tree detail
Switch#show process cpu
If the troubleshooting goes to dead end, try to shutdown interfaces based on “Switch#show cdp neighbors” output to find the loop.
If you find the above looks familiar, study the CCNP yourself, you might write some fancier ones 🙂