More Info:
Tips, Names and screennames, Interests and other information, Friends of friends

Names and screennames
Try searching on the person's name first. However, this will not always bring up the person you are looking for as people don't always put their full name on their profile. For example, if you do a myspace people search, many people are using screennames and not their full name. If you don't get the person you are looking for, try variations of the name such as removing the last name or using a nickname. Also try location to help narrow the search results.
Interests and other information
If a name and location search don't turn up the person you are looking for, try searching using other information as well. Try to be as specific as possible to start with and make the search more general if the results are too narrow. You can try to refine the results by adding interests you know that the person is interested in – such as favorite movies or hobbies.
Friends of friends
Groups of friends often stick together. You can also try searching for someone by searching for mutual friends or people that you know are their friends and trying to find the person on their friend lists. You can then contact the person. This is called foafing (friend of a friend) and is a common way to re-connect with lost friends.