Even on the most formal of ships, a dark suit and tie are fine for the dressiest occasions. If you do want to dress to the nines, many ships offer tuxedo rental services. Cruising is ideal for people traveling alone, because it's so easy to meet other people. In fact, most ships have parties just for singles early on, so you can get to know people right away. Many ships even offer gentlemen hosts who can be dance partners, dinner companions or a fourth at cards.
Most ships also have single cabins as well as single rates for double staterooms.
Most ships have 110-volt outlets in the staterooms. But do check with your travel agent or agency to be sure. Most ships even feature hair-dryers in your cabin. But most ships have two seatings, which differ only by time. Whichever seating you choose, remember that one of the best ways to make new friends is to ask for a large table.