Focus on the positives. Don't reveal anything that would paint you in a negative light. If there were reasons which might sound defamatory towards yourself or others, try to keep those details to yourself. For example, when someone has outgrown a position and it isn't advancing their career, looking for career growth elsewhere reveals a dedication to one's well-formulated career plans. Not burning bridges, and revealing professional appreciation for what you gained from your previous employers can go a long way toward exhibiting emotional maturity.

"When I interviewed for my last job, it was a temp assignment. After they saw my work ethic firsthand, they offered me a permanent role in their company. I explained to them I had clear goals, and it seemed the position they offered me only took me so far down my career path. We recently reached a crossroads, and I ultimately decided it was time to continue down that path elsewhere. I gave them two months' notice and have fully trained my successor. I am grateful for what I learned and the relationships I've built."