Before you search, it's a good idea to take some time and write down some keywords for your topic. You should include synonyms because many times databases will index articles that apply to your topic under synonyms. For example, film, movie, cinema, motion-picture are four words that describe a similar concept. Don't get stuck on one term and think of alternate terms or even related concepts.
When you search, often times the database or search engine you are using may index articles under different forms of the word. For example banking and bankers. In order to avoid missing out on some good results, you should try truncating your search topic. In the above case, you'd revert to a root, such as bank and place an asterisk after it, like this: bank*. This will retrieve all variant endings of a word, including bank, banks, bankers, banking
Be careful of truncating too much, which may lead to results you don't want.
In some databases you can substitute a "?" character for a letter, to search for variant spellings and combinations. By inputting wom?n into your search, you are searching for woman and women.