It is a good idea to first think about your main search concepts e.g. if you are researching the rights of child refugees in Britain, your concepts are rights, children, refugees and Britain.
Strictly speaking you should put an AND between each concept when you search a database so that the database knows that you only want items which include all of your concepts. Many modern databases will guess that you mean AND even if you don’t remember to enter it. However, some of the newspaper databases are quite old fashioned and do require AND so its a good idea to get into the habit of adding it.
Its also important to think of alternative terms which may have been used. For example, there are lots of alternative words for children such as minors, juveniles and youths. To ensure that you pick up results which include any of these terms, you need to use OR between them.
When you are using AND (to combine distinct concepts) and OR (for alternative words) within the same search string, put the words combined with OR within parentheses. This helps the database to understand which terms are alternatives.
You can replace AND in your search with a proximity operator.
Proximity operators will ensure that the words that you enter must appear near to one another. This avoids the scenario where one of your keywords appears on page 1 of the newspaper and another on page 7 with no relation to the first. This is particularly useful in the historical databases where often you search the whole newspaper rather than individual articles.
Unlike the other operators, the proximity operator is only available in some databases and uses different notation from one database to another. For example, some databases use the proximity operator NEAR, others user SAME and others use w/n (where n is a number of words). To find out if a particular database allows proximity searching and what notation you should use, read the Help section in each database.