I agree with both above posters, but I would also suggest looking into colour temperature and perhaps on the subjects themselves. For example, in the first picture, the bride's dress is yellow, some of the foliage is warm green and some is a cold green. In the last two pictures the subjects disappear from focus slightly due to the strong background and mellow foreground.
That said, don't get me wrong - they are by no means bad shots (and I think you know that!), just some thoughts on what you could look into.