1. Use descriptive filenames – This is the easiest way to start associating keywords with your image. Instead of using a filename like Img004.jpg, determine which keywords you would like the image to rank for and use these in the filename. For example if you’re trying to optimize images for a florist, a good filename might be red-roses-florist.jpg.
   
2. Use the alt tag – The alt text tag is used to describe your image and can be another good place to associate keywords with your images. Write a short, keyword rich sentence describing your image and include this as your alt tag.
   
3. Write a caption for your image – Google will also take into account text surrounding your image, so if you want to take your image SEO one step further you might try writing a caption that includes related keywords for each image.
   
4. Provide a direct link to the image – If you’re writing a press release or news article, including an image makes the story more appealing to readers and gives these publishers an opportunity to link straight to the image on your website.

And finally, one bonus tip: Register with Google image labeler. Image labeler is a tool used by Google to try and improve image search by allowing humans to associate specific keywords with different images. By including your image in the program, different people can select keywords associated with your image which can be included in Google’s image search algorithm.

To join this program, log in to your Google Webmaster account and click on tools, then enhanced image search. If you’ve got any other tips, feel free to leave them via the comments below!