I have pictures of Bricks/Stones and Clouds I would like to share these with you at some point. 
 
Now I understand seamless should mean that the edges of the picture should line up with other edges to make them seamless, but this is not always possible is there a  trick to make them seamless?? and the ones that I have with clouds in them... if the edges are simply the blue sky is that good enough to be considered seamless??