I’am going to list few Free WordPress themes which are great to use on your blog or website. Usually all modern WordPress themes being developed are SEO optimized so no need to worry about it. Its better to use free templates and/or try the free ones and then can be upgraded to paid version if the template best suits you. We can add/update CSS code to make it look better as per out requirement. And believe me its absolutely great working on CSS tweaking. Learning to make CSS changes is always fun and that too on our own blog is amazing, I just love it.