On the website Creativity-Portal.com, search for "free word search template" to download a template in PDF format used to create a puzzle with between 10 and 20 words. The website Spelling-Help-Online.com has a variety of templates to create a six-by-seven square grid for a word search with nine words, up to a 15-by-16 square grid for a 20-word puzzle. From the main menu, click on Fun Word Searches and then click on Blank Work Search to download.
Templates for word search puzzles consist of empty grids of squares to fill out by hand. An alternative method is using a program such as Word or Excel to create your own word search grid of any size. This method would also give flexibility to create uniquely shaped word searches for a special occasion or holiday, such as one in the shape of a heart for Valentine's Day, or in the shape of a school's mascot for Spirit Week.
The methods above still require you to fit the list of words into the grid yourself. At the website Puzzlemaker.DiscoveryEducation.com, there is a free online tool that will create an entire word search puzzle from scratch. Enter a title, the grid size desired and a list of words, and the program creates a word search in your choice of HTML or text format.