A few things have creeped up lately...
1. Double, even triple check, that the applicant meets the requirements for the rating sought. If a regs states a cross country needs to be at least 100 NM or needs to get at least 250 NM from the original point of departure then make sure those cross country meets those requirements. If the requirements are not met, we cannot do the checkride! Even if it's 1 mile short, a DPE cannot accept it. (Most DPEs I know use a couple different sources to check distances to ensure the requirement(s) are met).
2. Flight Instructor checkrides: The Instructor applicant must be able to TEACH! The instruction must be accurate, precise and relevant to the subject matter. The FAA PTS say there can be NO prompting from the Examiner. If you don't know an answer to a question, don't BS the DPE, he/she knows better. Use your resources to help you out.
3. Weather information continues to be a soft spot: Basic knowledge of Cold & Warm frontal weather and being able to identify Cold/Warm fronts on a chart has continued to be a soft spot on all checkrides.
4. Know your equipment. Every once and a while we'll see an applicant that does not know a thing about the navigation equipment installed in the aircraft. Interestingly, a fellow DPE has had 3 applicant shows up not knowing how to use a VOR. I've had several issues with Garmin 430 knowledge. There is more to an IFR GPS than the "Direct" button. One of the interesting problems occurs when you have an aircraft with several features that don’t work well with each other. For example, the integration of an Aspen System, a Meget Autopilot, and a G-430W. A complex system with some issues that need to be addressed before a checkride!
5. Emergencies: First rule...Fly the Aircraft!......Aviate, Navigate and Communicate .......Nuff said!