When you are raiding or playing an arena or battleground in "World of Warcraft," it can be disastrous for your game if you suddenly lose your cursor. Making the cursor bigger will make it more noticeable, so you will be less likely to lose track of it in a critical moment. Unfortunately, however, it is not possible to literally resize the cursor graphic itself, as it is limited to dimensions of 32 by 32. However, there is an add-on called "_Cursor" which can help you, by making the entire cursor more noticeable by adding trails to it.
Download the add-on "_Cursor" from your favourite "World of Warcraft" add-ons database. The add-on is available at WoWInterface and Curse, though it may become available on other sites, too.
Extract the folder contained within the downloaded archive to your game's Interface folder. Do not copy it do the "Addons" folder within the "Interface" folder as you would do with other add-ons. The interface folder is located in "C:\Program Files (x86)\World of Warcraft\Interface" on 64-bit systems and "C:\Program Files\World of Warcraft\Interface" on 32-bit systems.
Start the game. As soon as you do so, you should easily be able to see the cursor now, since the entire graphic is larger and more noticeable with the addition of pointer trails.
Configure the _Cursor add-on by typing "/cursor" when logged in and with a character loaded.