Here's a hint to diversions that might help you out. As soon as your DE (or CFI for that matter) tells you to divert, take note of the time to the nearest minute and mark EXACTLY where you are. I've seen several CFI's leave that out when they're teaching their students. To get a ballpark heading, look at your new destination and where you are. Hold a pencil connecting the two, then keep it pointed the same way. If you slide it over to a VOR you have your intitial heading that you can turn to and THEN do all of the math after you are headed towards the new destination.

Then come the exact calculations. Get the plotter to measure your course and distance. You should already have your winds aloft. Use those and your cruise speed and plug it into your E6B and voila, there you have it. I'll give you some advice here. If it looks like you aren't on course with your computed heading, you can always use pilotage to find the way. You could tell your DE something like "Well, it looks like these winds aloft are a little off today, so I'm going to steer 20 degrees right to get us where we need to go." How often have you seen winds aloft that are exact to the forecast? Especially if you're at an altitude of 4,500 and you are in between two stations. Show the DE you know what you're doing.

Your DE will let you know where you will be planning your XC to for the checkride. If you schedule the ride a week or so in advance, you can plan your XC and look for airports in the vicinity on your sectional. If it makes you feel better, have your CFI go up with you and practice one or two diversions in that area. Also, some DE's are notorious for having favorites for the X/C and diversion. Get the gouge on your DE if you can, it could really help out.

Ok, my novel is finito. I'll leave you with my last but most important piece of advice. FLY THE AIRPLANE first. Throughout all of the fumbling through charts, plotters, E6B's, etc... make sure you maintain positive control of tha aircraft. Stay on your heading and altitude while keeping your head out of the cockpit. Good luck and let us know how it goes!