LUA Scripting - When to check session readiness?

Hi all, I am coding and IVR on LUA. Based on the freeswitch books you have to check session readiness to avoid getting stack in a nasty error or infinite loop. That is OK. My question is: when should I do it? What I am doing now is to check it before asking caller for feedback or querying a Web Service. Does it make sense? It bothers me that the code gets really cluttered b the constant checking (LUA code layout does not help either). I am very aware this is not exact science, I just want to know the opinion of more experienced people out there. Thanks! Wilmar