My answers to these questions would depend entirely on what the job was as I would try and link the answers into the field of work I was applying for. I know this sounds a bit vague but my greatest achievement as a midwife would sound rubbish if I was applying for a job as a car sales person!
If you get asked " How did you prepare for this interview?" say that you have read up about the compnay, done research, looked in library etc.
Do NOT say " Well, i got up a bit earlier, had a shower and wore my new suit."