On my site I want the image that I post at the top of posts to appear on the index page, but as a thumbnail. I thought it would be quite simple to do, but I haven't found a solution yet. I have managed to get half a solution. I used the "Set featured image" option and it sets my image as a thumbnail on the homepage. However when I add the image to the post, that appears on the homepage as well next to the thumbnail. I don't want two of every image to appear on the homepage. Does anyone know how to solve this? Thank you!
If I understand what you want to accomplish, this discussion should have what you need: http://wordpress.org/support/topic/excluding-images-from-posts-on-homepage