I've found that if I assign a switch to flaps cycle and the switch in the cockpit is on full or half, my assigned button won't cycle the flaps. I have to reach down in the virtual cockpit to switch it to auto. then my button works. I'm sure that there is a better way, but alas....
You REALLY need to know what your flaps condition is to do the ball flying properly. The flaps position will determine your on-speed parameters. Make sure you are at full flaps. It's silly to get into the nitty-gritty with the other stuff and not know where the flaps are. Another thing to always be aware of is your fuel state and remaining weapons load out. Makes a massive difference in approach speeds. Even though the speed is not part of your scan, the jet will fly differently with different weight loads and flap conditions. Remember the max trap weight also so you can dump fuel if need be.