From time to time you'll be asked to do the impossible when it comes to using your design skills. This may leave you shaking your head but as a design service provider it's your job to make the client happy. What do I mean by impossible? Let's say you've got a horizontal banner ad to be place on local website portal and the client sends over the needed artwork to get the job done. Right off the bat you realize the imagery simply won't work. It's a huge vertical image that if used in the horizontal space will look like nothing more than a couple color blocks. or it will only be visible on one side and not all the way across. We as designers know this won't work but it's up to us to educate the masses as to why (as if common sense wasn't that common).
In my experience it's usually one of the following examples:
Vertical image in a horizontal space
Horizontal image in a vertical space
Too much content for the room provided or allowed
Though they sound like common sense most clients aren't really thinking about how it's going to work. They're thinking about what content they want and they expect you to make it work, or else find a viable alternative. The challenge is then giving them exactly what they want. The only real way to do this is clear communication with the client and some basic client education to keep this from happening in the future. Instead of simply saying "no, this won't work" offer helpful alternatives and options. You'll be seen as someone who's willing to work with it instead of another person to butt heads with.