Good resolutions for backgrounds and textures?

Good resolutions for backgrounds and textures?

Boom Shaka's picture

I'm experimenting with some backgrounds and textures that I think may be good enough to submit....are there any recommended resolution/sizes?  

 

I'm assuming I should probably do the backgrounds in a 3:2 ratio but not exactly sure how big is too big or how small is too small?

 

Same on seamless textures - make them larger and let others resize or make them to the size that I think looks best?

 

Thanks in advance.