If you are using a word processor you can and should italicize book titles. However, if you are using a t, I don’t see how you can use italics. Before word processors came into common usage, it used to be the standard practice to underline book titles when typing. This indicated that these titles should be in italics if the manuscript was published in a book, magazine, or newspaper. If you are writing something in longhand you should also underline book titles, but I don’t see how you could have any other choice, unless you happen to be artistically gifted and can make your handwriting look like italics when you want to. There may be some typewriters which allow you to switch from regular typeface to italics, but I have never seen one. No doubt the IBM Selectrics could be used to type book titles in italics if you switched from one ball to another and then back again, but that seems awfully time-consuming. 

Assuming that you are typing, always italicize a book title. However, if you are handwriting a draft, it should be underlined.

When you’re writing an essay, make sure you italicize the book title instead of underlining, bolding, parentheses, or using quotation marks. 

Book titles are italicized. If you are using a typewriter and can’t write in italics, then it is customary to underline the title.  Same applies to plays. Titles of poems, short stories, essays, and other short pieces are set off in double quotes. George Orwell’s “Shooting an Elephant” would be in quotes, since it is only an essay. Commas and periods go inside the closing quotation mark, as for example with Orwell’s “Shooting an Elephant.” The English do it differently and this can create some confusion, but observe the usage in American publications.

It occurs to me that you might be referring to a collection of essays by Orwell in a book that just has the title Shooting an Elephant derived from the title of the essay. If it is a book title it should be italicized.