Part of understanding God's story through His Word is to grasp how transformative it is for our lives. In Second Timothy 3:16-17 Paul writes:
"All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work."
The way we get to those profits is through finding applicable truths, use them to evaluate our lives and, as a result, choose to become more conformed to God's character and will. These are our takeaways and life truths we will grasp and apply every time we study God's Word. Therefore, application should be handled with reverent caution.
The most important rule of application is making sure you have observed and interpreted Scripture by studying it thoroughly prior to making applications. If you try to infer applications before you study, you could miss the whole truth of what God is communicating. If you don't do it at all, then you're pursuing knowledge of God but not what God is asking of you.
Applications can be internal or external:
Internal applications are usually about changing the way we think, making sure we believe true things about God and ourselves.
External applications are more behavioral and change how we live and interact with others. You should read through an entire passage and list the ways you can personally apply what you've learned to your life right now, being as specific as possible. You can write your application in the form of a question, or you can write your application as an "I will" statement.