The introduction is the most important part of an essay. A person decides whether the essay is well written and useful while reading its introduction. Keeping this in mind the introduction should be entertaining as well as eye catchy. It should give a brief idea about the topic to be dealt in its body.
Do proper research and gather enough information about the topic you need to work on. This will give you a clear idea and the points to be dealt with. Asking questions or using quotation might be quite easy way to start with. Introduction should be kept brief so that the reader knows that lot of it is, yet to come. While asking questions in introduction, keep in mind that it needs to be answered in the body of the essay.
Give importance to grammar and spellings. After completion of the work, it should be read aloud to detect the mistakes done. Editing and re-editing is required to get a perfect error free essay.