Long gone are the days of employees spending 40 years in service to the same company. Some experts now say that you should plan to change employment every three to five years to continue to advance and grow. Whenever it comes time to leave your job, you’ll want to make a graceful exit both as a professional courtesy and in consideration of your reputation.

Recently, I was horrified to read an online thread about the “quickest you’ve ever left a job,” which included the story of an employee breaking for lunch and never returning. The thread gave me a pretty solid list of what not to do, including making a sudden exit, bad mouthing your coworkers or boss, leaving projects unfinished and the company stuck, and recruiting past co-workers to leave along with you.

For an employer, someone leaving doesn’t have to lead to catastrophe. But when person exiting offers a toxic attitude or an abrupt departure, it causes a disruption for the whole team and business.

That’s why you should always give notice to allow for a transition. The unspoken industry standard for most positions is two weeks but you may want to allow for more time if you’re in a key position or in the midst of a big project. Some people would advise not to leave until you’ve completed major projects, but we know that those can roll into another all too often. In reality, there may never be a best time to leave, so give your employer enough notice to find a replacement and work with you on unfinished projects.

Speaking of your projects and tasks, be ready to train a replacement or create a training manual that can be used to onboard the new staffer. It’s a good thing for every company to create for each position, but as you’re exiting it can be invaluable to your past employer — something that will create goodwill long after you’re gone.

Related: Digitize Your Operating Manual

Even if you’re not looking to leave, creating such a list of responsibilities and details on your job can improve your resume as you review your work tasks and results. At my last desk job, this manual was an ongoing process. When it came time to update my resume, instead of simply adding “detail oriented,” I knew to write “paid invoices and expenses for 39 facilities, with an average of 550 invoices per month, without incurring late fees or errors, and saving the company both time and money.”

Hint: even if you’re happy at your current place of employment, such an exercise can show your supervisor how much you’ve grown in the position to warrant a raise or promotion. Remember, if you’re irreplaceable then you can never advance.

No matter your reasons for moving on, stay connected with your coworkers and supervisor via an appropriate medium, such as LinkedIn. LinkedIn is designed for these professional relationships and can allow those you’ve worked with to endorse your skills and serve as a touchstone back to the industry.

As you’re leaving, there might be a lot of relief, especially if you’ve struggled and felt held back. But now is not the time to publicly air your complaints. Even vague Facebook comments have a way of making it back to bosses and can sink your reputation. While you don’t know where your future will take you, it’s just not worth the struggle of fighting a reputation as a whiner or ungrateful.

Finally, some companies are fond of the exit interview and what you say on your final day will resonate, so speak carefully. You could use this as an opportunity to share all the things you would have changed, but then you risk being seen as someone who lacks real investment in seeing changes implemented. Instead of pretending that all is well, prepare two or three suggestions that would have helped you do your job, created a better environment or improved communication. In most cases, your ideas and suggestions are only relevant if you’re going to maintain some relationship with the company. Otherwise, it’s just an awkward breakup conversation during which you tell the other party all they should have done to keep you around.

If you make a strategic and thoughtful exit, and move on with a good reputation for being reliable and polite, it’s worth the effort in the long run. Rushing out the door, talking about how glad you are to be gone and leaving a mess in your wake, can might counteract all the effort you’ve put in during your tenure. Choose wisely.