Keep up with the changes, become adpatable to your profession, always learn new skills, have a solid work history and dont ever do anything that could be considered misconduct (something that would get you terminated immediately: fighting, threatening, lying, violating policy, etc).
I refresh my resume every 6 months. Not to start looking elsewhere but to gauge if my skills are improving and if I warrant more accountability, responsibility and especially $. If its plateaued its probably time to look elsewhere.