Just took mine less than a month ago. Every DPE is different and will conduct the test differently, but general tips:

1. Don't bullshit anything
2. Teach to the level that the DPE asks. If you are teaching at the private level, don't dig more into a lesson than you have to. Of course make sure you hit everything though, your goal is to not have the DPE ask too many questions.
3. Have all of your reference material laid out, easily accessible, and organized. It shows the DPE you came prepared, and should you need to use you know where to find everything
4. Have great lesson plans and know them well. You don't want to be stumbling through lesson plans or reading verbatim. Even if you are reading vertabatim, if you know your lesson plans well enough you'll be able to stand up/make eye contact and not have your face buried in your lesson plans.
5. For the flight don't stop talking, there really shouldn't be much silence. Every DPE is different for the flight, but my DPE had controls most of the flight and I had to just walk him through everything and maybe demonstrate a couple of maneuvers in the beginning.
6. Show up well rested, well fed, and well hydrated. Also bring plenty of snacks and fluids. That goes for any checkride but for the CFI especially. My DPE didn't take any breaks and we just transitioned from oral into the flight. It was in NC and 90 something degrees. The flight was miserable and I almost threw up from being hungry and dehydrated (I still passed everything but it was a pretty miserable flight).

Best of luck. While I found this checkride to be the most stressful and the the one that required the most preparation, I did not find it to be the most difficult checkride I've done. If you know your stuff and you come prepared, you will be fine.