Reducing outside interruptions is crucial to premium performance at work. But what can you do if phone calls, visits from co-workers and rambling meetings waste hours of your work time every day?

“You can defend yourself by learning simple techniques that will help you manage time-wasters,” says Stephanie Winston, president of The Organizing Principle, a management consulting firm in New York, and author of The Organized Executive. “And you can establish greater control without being rude or shutting yourself off from others’ needs.”

The following suggestions will help you gain control of your worst time-wasters.

On the phone

Keep calls brief. Get to the point immediately when you’re making or returning a business call. Develop strategies for dealing with long-winded people, such as beginning calls with, “This is Mary. I have a meeting in 10 minutes. What can I do for you?”

Consolidate call-backs. Return all your calls at a given time each day. Begin with priority calls and work down the list.

Return calls when people are less likely to chat. For example, call right before lunch or near the end of the day.

Develop a message-tracking system. If you’re disorganized, you may spend more time looking for your messages than returning them. Avoid putting message slips under a paperweight or in your in-box; they tend to get lost. Instead, use an old-fashioned desk needle or add important calls that must be returned to your master to-do list.

Drop-in visitors

Interoffice visits are a part of office life. The following strategies can help you regain control if you’re constantly interrupted:

Send a clear message. Close your office door or post a note on the entrance to your cubicle saying you’re busy until a certain time. You’ll deter all but the most insistent visitors.

If your desk faces the door or a corridor, re-position it so a passerby can’t easily catch your eye.

Consolidate visits. Limit appointments to a specific block of time each day or week.

Set time limits. Limiting spur-of-the-moment sessions without being rude requires tact, but it can be done. When someone asks if you have a minute, you can respond with, “Could it wait until this afternoon? I’m really swamped right now.”

Confer in colleagues’ offices. When co-workers want to discuss projects with you, offer to meet in their offices. “It’s much easier to excuse yourself than to ease someone out of your office,” Ms. Winston says.

Endless meetings

Eliminate unnecessary meetings. Before calling a meeting, ask yourself if the issue could be handled by a memo, telephone call or informal conference.

Distribute an agenda in advance. List the topics to be discussed and note any papers, figures and information people should bring.

Set time limits. Try to schedule meetings just before lunch or quitting time. Doing so will curb a tendency for attendees to ramble on.

Take control. If you’re the moderator, limit the discussion to topics on the agenda. Unstructured meetings are usually unproductive.

“By learning to define your time as your own,” Ms. Winston says, “you are then free to enthusiastically speak and meet with co-workers, clients and other contacts without compromising your own productivity.”