I am a big believer in Differentiating instruction and have read a lot of books on the subject and I have attended National conferences on D.I. as well.
However when you mention the term Differentiation to some teachers they tend to get scared off. After all change is scary and people fear the unknown.
While there are many fancy definitions and terms related to D.I. I think it can be boiled down to good teaching.
Ask yourself the following
1. Do you think it is important to know each of your students
2. Do you think it is important ot teach each student as an individual and meet his/her needs
3 Should your lesson be driven by Student readiness and understanding, and therefore do you think it is important to know what your students have learned.
4. Do you believe all students learn differently and therefore need to be taught differently
5 Do you think the focus is student centered and student learning and not teacher centered.
I would hope almost all teachers would say Yes to these questions since these questions reflect Good Teaching. Well let me tell you a little secret if you said Yes to these questions then you are either are or need to be differentiating your instruction.
My quick thoughts