In essence: Act like the boss you want to be. Here's how:
Don't slack off. Maybe you're giddy about returning to campus. Or if you're out of school, maybe you're distracted with finding your next job or internship. But showing decreased enthusiasm at the end of your internship, or worse -- leaving assignments incomplete -- is a major no-no. Plus, you really don't want to slack off as you ask your boss to write a letter of recommendation. Until the end of the last day of that internship, you need to put 100 percent effort forward.
Do something noteworthy. Go out with a bang, creating a manual of your job responsibilities, along with a step-by-step workbook of your daily activities. This may help whoever inherits your duties and will leave a lasting impression with your boss, adding that you should make every effort to complete pending projects. Offer to answer questions about your duties after you've left, which will show your co-workers and boss that you genuinely care about the company and want everything to run smoothly.
Ask for feedback. Exit evaluations are built into some internship programs, but if that's not the case for yours, have a 15-minute meeting with your boss before you leave. Ask about your performance and your strengths and weaknesses, suggests. When discussing areas of improvement, thicken your skin and appreciate the value of the critique. Constructive criticism is actually a good thing. "It gives you something to work on, and it can help you really build your goals for your next professional experience.
Say thank you. Emailing co-workers to thank them for their involvement in your great internship experience. Provide your contact information, and snag their personal email addresses, in case they leave the company. Follow these emails with a handwritten note, which you should keep short, sweet and to the point. Thank them for their time, reference a special moment you shared and note that you'll be in touch. And then, of course, be in touch. Shooting your colleagues a short note around the holidays and another in the spring, so they remember who you are and receive an update on your activities.
Express your interest in a future job (if you have such interest). Don't assume this is a given. You have to make sure your boss knows you want to work at that company. In a very polite and professional way, let the employer know that this is your dream job, and you're interested in pursuing a career at the company -- if that's the case.
Secure a reference or two. Listing references from this internship will show future employers that you were confident enough in your work to ask others to recommend you. But use some caution and confirm -- don't assume -- this person will happily vouch for you in the future. Always ask if he or she would feel comfortable serving as your reference first.
Ask for a letter of recommendation. While a reference will speak on your behalf should a prospective employer call, a letter of recommendation is typically more useful for academic opportunities, like when applying to graduate schools. I would really only save this for someone who you worked closely with. If it was a direct manager, and you worked with them everyday, and they told you were doing a good job and gave feedback, then I would definitely go for it.
The more time you can save this person as he or she composes your letter, the better. Send bullet points covering the work you've done or even a letter template, so he or she can fill in the gaps and sign it. Ask for the letter sooner rather than later, while you and your excellent achievements are fresh in the his or her mind.
Snag a LinkedIn endorsement. While you're gathering affirmations of your hard work, make sure to get some LinkedIn love, too. First updating your profile to include your current internship. Then ask your boss to write a two- or three-sentence recommendation. Once again, the key is to make this task as quick and painless as possible for your boss. Send them all the information, mentioning hyperlinks and a sample recommendation. So they have to make no more than like two or three clicks, and it's done.
After you leave, track your company. Set up Google Alerts for your colleagues, company and company's clients. That way you'll receive an email every time those names appear on the Web. Say the public relations firm you interned with works with Client Z, and you get an alert that Client Z was mentioned in The New York Times. Email your colleagues a congratulatory note on the client's good press. Or perhaps you're alerted when your former internship coordinator is promoted or quoted in a blog -- another excuse to drop a line. Staying up to date shows you're paying attention, you're doing your homework and still have great interest in the company.
And finally, leave like a boss. Don't rush out of there in a hurry and leave like the building is on fire, pointing out that even if you're excited to go back to campus or begin new professional experiences, the internship shouldn't have just been a temp job or bullet on your résumé. The work you've done was, in part, to build a network. Leave your colleagues on a humble, thankful note. Before walking out the door, make one more round through the office and say a genuine goodbye. The extra effort will go a long way in building future goodwill.