For example lets say my 1,000 word article is about acne and my main goal is to rank for the long tail "how to treat acne overnight". So for SEO I use the title "How to Treat Acne Overnight Using Simple Methods", and then I use "how to treat acne overnight" somewhere in my first 2 sentences, and then once more in the article. Now should my file name be called "how-to-treat-acne-overnight.jpg? Or should it be my title name? And what should I use for an alt tag? The title of my post or the long tail keyword? Also I will only be using only one main image in my post since it's only 1,000 words at most. Thanks for any help.