The only person that will manage and grow your career is you. Maintaining and regularly cultivating the documents (resumes, cover letters, etc) is like a bonsai tree. Spending a bunch of time working on these when you suddenly need them is a great way to lose valuable time and it may cost you an opportunity that you really want. Doing regular small items (trimming) keeps the tree growing and looking good. It’s also a good way to reflect on where you’ve been, what has been achieved and the destination of your hard work.
I have taken on the habit of regularly updating my LinkedIn profile / resume at least 1 time per year. It is much easier to maintain this stuff when it’s fresh in my mind and take it as a small task when information is easy to gather. I’ve found that having to go back more than a year to remember accomplishments as well as changes in role or responsibility, when my title may not change, are much harder to get correct. I can also ask people to give comments and recommendations while things are fresh for them as well.
This year was a bit of a unique experience as it apparently freaked a few people out when I asked for recommendations of my work. I had put in my request that I was not actively looking for new work and this was part of my regular process, as I had several people, including my current manager, ask what was going on. I guess some did not read that part after the form letter bits from LinkedIn. So a possible modification to the process is to give people are more personalize heads up.