Oral:
- Lost Comms is the biggest part... they'll probably give you a scenario "you're on this flightplan and you lose comms at the XXX VOR while in IMC, what would you do"
- Be sure you can pull out an IAP/enroute chart and identify everything on the chart.

Flight:
- Be careful on your DME Arc... those twist a lot of students around, especially if you haven't been practicing them for long. Think through it before you start turning.
- The examiner will likely talk MUCH less than your CFI did. They may not talk to you during the approach at all. If they don't say anything near MDA/DH, don't forget to go missed at the appropriate point.

Good luck! The IFR rating is, in my opinion, the most fun type of flying you'll ever do (once you get that hood off).