Vincent Tsui for HBR

Around 75% of college students, at some point, work in an internship. These experiences can be tremendously valuable, providing young workers the opportunity to build skills for their resumes and meet people who are working in their preferred industry. Increasingly, they are the likeliest route to full-time employment and are even offered year-round rather than only during summer months. But they can also be difficult adjustments for young people who have little to no experience in professional offices. It can be hard for someone to stand out and make the right impression during a three-month stint spent adapting to such a new environment.

How can interns learn what they need to know, impress those they work for, and secure a job recommendation or full-time offer in such a brief period of time? I consulted 20 professionals who have worked with or supervised interns in higher education, business, law, and nonprofits, and compiled the most valuable advice for interns from their stories, my own observations, and management literature. This advice won’t cover everything, but it does offer a starting point for interns.

Start with relentless punctuality. Show up on time (or early) in the morning, arrive for meetings before they begin, and complete tasks by their deadlines. When I asked professional contacts for their advice to interns, they consistently listed punctuality as a critical success factor. Ryan, an executive in a municipal government, says, “Always be on time. Summer internships are for a short, defined period of time, so give it 100%. Be willing to get to the office early and stay late.” As an intern, you are both a guest in a new environment and a colleague on whom others must rely — make sure that you respect those colleagues by being on time.

Complete each task with excellence. Whether an assignment is mundane or exotic, pursue it with relentless drive and a determination to exceed. If you’re asked to make coffee, make the best coffee your colleagues have ever had. If you’re asked to make an Excel model, over-invest your time and effort in assuring it’s right, aesthetically appealing, and thorough. Amy, a food and beverage executive puts it this way, “Finish the assignment or project with excellence — anything else you do is bonus, but please start with the assignment given.” Even if the project seems small or unimportant, do not give in to the temptation to complete it with anything less than your best, and don’t decline a project just because it doesn’t interest you. Katie, a tech industry executive cautions to “[never] say no to small opportunities because [they don’t] fit your idea of work.” Repeated, enthusiastic, and excellent delivery of assigned tasks is the building block upon which everything else in your internship will rest.

Take on more work — without being asked. Use excess time to take on new and important work, assignments others don’t want, or projects that are needed but not yet clearly defined. A nonprofit healthcare executive counsels, “When you see something you can do, do it.” I still remember the names of interns I’ve worked with who never let themselves sit idle and took on new projects with little or no guidance. Gary, a finance executive, told me, “Sitting at the desk checking your most recent Twitter feed while you wait for someone to give you something to do is one of the best ways to not get an invite back.” Deliver what no one is expecting — or what no one else is willing to do — and you’ll not only be appreciated, but remembered.

Be resourceful. Research a topic thoroughly before asking a full-time colleague or manager for help, and take the time to reflect and come up with your own insight or solution before consulting others when you uncover a problem. Amy, the food and beverage executive above, recommends, “Look for the resources you need on the internal websites or ask other interns before [asking] your coach.” She notes that it’s a mistake to “ask too many questions that show you didn’t even try to look for the answer yourself.” It’s critical that your colleagues view you as someone who is resourceful and independent enough to bring something new to the table instead of just stopping every time there is a bump in the road.

Ask questions — good ones. The hallmark of an intellectually curious, diligent colleague is the quality of his or her questions. Renowned management thinker Clay Christensen recommends spending time formulating the right questions. Ben, a management consultant, agrees: “Think — in advance — of questions to ask. If you are meeting with a peer or superior, think of thoughtful questions you can ask to demonstrate you’ve prepared for the meeting and respect her time.” If you’re in a meeting with senior colleagues, think less about your answers to their questions and more about what you see missing — the questions no one else is asking. When you hear someone ask a great, conversation-altering question, write it down and reflect on what made it so special. And, as a rule of thumb, make sure you ask one or more authentic questions in every meeting you attend. Following this advice will hone your ability to ask questions that lead to real insight and will ingrain in you the essential habit of intellectual curiosity.

Build professional relationships. Internships usually last only a few months, and in that context, it’s easy to either focus solely on your work or to make connections only with the other interns working around you. But forming broad, deep relationships within your team and throughout the organization can help you manage your current responsibilities while also boosting personal development. You’ll also make yourself more memorable to those around you and create a network of contacts to reach out to when you’re ready to find your next job. Invite colleagues to lunch. Ask them questions in informational interviews. Offer to help where you can. Observe the great relationship-builders in your firm and learn from them.

Internships are hard work. And doing only what’s expected of you isn’t enough to be noticed. You need to go above and beyond, from arriving on time to doing exemplary work, and make the most of your time in the organization.