Here's how to do it.

• Agent: Yes, you'll probably want to use one. Best to go with an agent that specializes in cruises with the companies you're considering and has either been on or previously booked clients on those ships. Look for one whose style matches that of group members. Before settling on an agent, ask specifically what kinds of upgrades and discounts he or she has arranged in the past on the ships you're considering. And ask him or her to keep you apprised of any specials that may be offered between the time you book and the time you make your final payment.

• Share the load: Assign roles and trade information; copying everyone on e-mail can help keep communication clear. No one person needs to do it all. At the same time, the group doesn't need to get involved with individual problems; those should be handled individually.

• Cabin location: If you want to be located together, be sure your agent knows and confirms this. The best cabins are generally considered to be mid-ship on the highest deck in your price range. Be sure your agent guarantees your cabin category in writing.

• Pricing: Be sure the ship you choose offers a range that suits all members of your group.

• Group discounts: Most large cruise lines require a minimum of seven cabins before they offer a discount. Smaller lines may have more liberal policies; at SeaDream Yacht Club, for instance, the sixth cabin is free (which you can use that savings to cut everyone's cost.)

• Dining: Be sure your agent confirms the seating and table arrangement you want early in the process, as large tables book quickly. If you want to eat together as a group in a ship's ''alternative'' restaurant, make sure you reserve it as early as possible.

• Travel insurance: It's best if each traveler chooses his/her own policy since circumstances vary. Experts advise booking with an independent travel insurer -- not your cruise line. You can find highly rated companies at www.insuremytrip.com; www.quotewright.com and www.squaremouth.com. NOTE: In most cases, you must buy your insurance within seven days of making your first trip payment to get coverage of existing conditions.

• Consider private shore tours: With four you can share a taxi; with six or more you can share a minibus and guide, often for the same or less than ship tours. Use your agent to help you find a reputable tour company or find one on your own through recommendations, websites and guidebooks. (We used a St. Petersburg agent that belongs to the highly regarded Virtuoso network, www.virtuoso.com.)

Increasingly, cruise lines are offering guests the ability to book private tours, though doing so on your own is generally cheaper. Be aware, though, that if you aren't traveling with a ship-arranged tour, you're out of luck if the tour is late and misses the boat. And cruise lines vet their operators, giving you an extra layer of security.

Whether you're traveling with a group or on your own, consider:

• Ship size: Large ships offer more activities and facilities -- but more lines and larger tour groups. Smaller ships offer a more intimate atmosphere and more specialized shore excursions -- but often cost more.

• Ship style: Do you want several formal nights, or none at all? Boisterous casinos or low-key chamber music? Each ship has a personality; be sure it matches that of your group.

• What's included: What is included in your basic fee, and what is extra? Depending on your lifestyle, a luxury ship that includes wine, liquor, tips and some excursions may be a better value than an cheaper cruise that charges extra for those items.

-- JANE WOOLDRIDGE