Thanks to all for taking the time to compile such excellent advice. One thing I learned during my training is that different instructors teach different things and all have their own pieces of experience to pass on. I think it's the duty of every pilot to never think they've learned it all, as there's always another experience out there from which we can learn something new. A constant learning process might save the lives of us and our passengers one day. Who knows?
One of my own experiences regarding mobile phones: I was flying along with my instructor and we kept getting interference on the radio. It was my mobile phone. I'd say it was more an annoyance than it was a safety concern, but I turned it off anyway. The advice above to leave it on is good if you have a flight safe mode (as I assume this prevents the interference).
Another issue I once had was not ensuring the primer was in and locked. During power checks the engine was shaking far more than it ought to have been, and we decided to taxi back to the apron to get it checked out. When back we ran through our checklists again and established that this was the thing causing the problem. So this backs up the point of always following through your checklists and never let anything distract you from it. Such distractions are more likely to make you forget steps or think you've done things you haven't.
Safe flying all!
