Burp has some nice export features which (combined with some 3rd party tools) can greatly aid in the process of looking for additional/hidden endpoints and/or hardcoded secrets.

It was already discussed here. Putting here for quick reference.

In the past, I found (already quite old - presented in 2013) slide deck Burp Suite Pro real-life tips & tricks authored by Nicolas Grégoire very useful which gave me motivation to constantly look for effciencies in my day to day Burp Suite Pro usage. Since that time Burp has significantly evolved (major milestone - version 2.x was released) and lots of interesting 3rd party extensions were developed.