I don't really remember what I did for Commercial single...it was an add-on anyways, so it was basically just a quick flight with the maneuvers.
As far as CFI, I'll give you my gouge, as best I can remember:
Oral:
The oral was quite tough. All through the entire CFI course, I didn't really make many lesson plans- I was more comfortable just reading the material the night before and then presenting it to my instructor. When the checkride came, the check pilot wanted me to have a lesson plan on Eights on Pylons, and present a lesson on them. Of course, I didn't have a lesson plan for those, but I did pretty well just improvising. He reaaaalllly dug into me though- I'm sure he thought he could trip me up on something, seeing as how I wasn't presenting it out of my notes or anything. I had to explain every singe minute detail of 8's on Pylons- everything from the general description, to the procedures, to the aerodynamics of the whole maneuver. I pulled it off OK. Besides that, he asked just a couple of FOI questions (sorry, can't remember what exactly now). He also ran through a few scenarios with regards to student pilot endorsements, and regulations related to soloing students. He had me briefly run through a couple of procedures, asking detailed questions all along the way. Thats about all I can remember- all in all the FOI stuff was pretty light, but other than that it was a very comprehensive oral. Took just under 2 hours.
Flight:
The flight in an Arrow, and was a piece of cake. The only checkride that I've had that was easier was CFII. I did about 85% of the flying. I demo'd a soft field takeoff. We climbed out, and en route to the practice area, he had me teach him how to make basic turns. He did them as I taught, wanting me to guide him through them. No biggie. After that I demo'd a chandelle, and then critiqued one that he performed. At altitude, I did steep turns, slow flight, an elevator trim stall and I think thats about it. Then for the engine failure, he actually cut my mixture (see
this thread - the "friend" was actually me- I was worried about burning bridges at the time, but now I don't give a hoot). Thinking that he was just pretending to be a student (but confused because beforehand he said he would be clear when he was acting as a student), I shoved it back to full-rich. He then cut it again, and stated it was a great way to simulate engine failures when a student has their hand on the throttle. I told him it was a great way to create a real engine failure, and then put it back to full-rich and pulled the throttle back instead. After that, emerg. procedure went fine. Once we got down low, he of course had me demo 8's on Pylons, and then critique him as he did them. On the way back to the airport, he had me "teach him" how to properly trim the aircraft. The flight ended with a short-field landing. I believe it was like 1.2 hrs.
Anyways, sorry I can't remember every single detail..but I guess this turned out long enough as it is. Good luck with your CFI, and of course, if you have any questions, I'd be more than happy to answer them to the best of my abilities.