Discuss with your wedding planner about the themes, colours and designs you want to create on your camera covers.
You can also search online about the selection of themes, colours and designs. This will take a little bit of your time and effort and you can pick some beautiful themes and designs.
You can work on themes on Photoshop to improve colours and measurement of the skin cover.
Create a template page and use all the photo, pictures and colours that will contribute to the theme. This will help you cover the camera the way you want.
Prepare the page carefully and make sure you have confidence about the format of the cover. Then print out the page and cut the borders carefully.
This makes your cover for the camera ready and you can wrap it in it.
Nowadays you might also find ready cover papers, based on different themes, including wedding. You can select one that you think will fit the best with your wedding colours and designs and use it on your wedding day.
Another way is to just leave the camera on the reception for your guests and see what choices and colours they come out with. Since many of them attend weddings frequently, they are likely to pick the colours themselves.
If you are confused or do not have idea what colours you should select for the customized camera covers, you can get help from a friend or your wedding designers.