In A Companion to Linear B: Mycenaean Greek Texts and their World vol. II, Yves Duhoux has written a must-read introduction for any aspiring philologist: “Interpreting the Linear B Records: Some Guidelines”.
His guidelines apply to far more than just Linear B. Whether its Linear A, the Byblos syllabary, Proto-Elamite … these guidelines are universal to creating a secure decipherment, and provide a methodical framework for sanity checking the strength of a hypothesis. They reinforce much of what Emmett L. Bennett, Jr., Alice Kober, Saul Levin and David W. Packard have also said on the topic.
I highly recommend reading the article (and the book!).