I've found a lot of value with canonical logging[0] for server-side logging.
Basically, we emit one log per request/response with appropriate severity level (INFO if request succeeded, ERROR if it failed) and the log contains all the interesting information that we care to log. This makes it very easy to track and debug issues at an individual request level, while not having to overly rely on external tools to parse/combine logs to reconstruct requests/sessions.
The other benefit of this is that we can feed these logs directly into log ingestion tools like Datadog and plot graphs, view distributions and set alerts on metrics present in logs.