Remember to check the complete reference and abstract for your article.
Check the language. Is the item you are requesting in English? If not, are you fluent in the language of publication? Many foreign journals are not available through ILL. Limiting your search to English will not exclude articles if the abstract is in English. If you do want an article in another language, please note that in the “notes” field of the ILL request.
Are you requesting a thesis/dissertation from another university? Most are not available through ILL.
Is the article only 1-2 pages long? You have probably located a conference abstract, a book review, or a letter to the editor. These short pieces are usually not helpful to you. Many journals print conference abstracts, so you might find these citations and think there is a full article.