Welcome to the Q&A Forum

That's a good rule of thumb from Brett Collins, though I typically make the alt attribute (technically it's an attribute to an image "tag" rather than a tag in and of itself, but it's just a semantics thing) descriptive of the image instead of the post - often it's the same thing either way. I know some people, myself included much of the time, who don't even use the title attribute unless it is within the href tag of a linking image. I know others who use it as the actual title of the image (e.g. funnydog.jpg would be "funny dog" and cats-are-evil.png would be "cats are evil"). I do typically make the alt and title attributes of an image two different things. I disable the creation of image attachment pages in Wordpress. When inserting individual images, ensure that the Link is set to File Url. When inserting a gallery, ensure that "Link thumbnails to" is set to Image File. You can also find plugins that will redirect the attachment pages. I typically block those in the robots.txt file too.