People have a tendency to like things that they used to see in past. It doesn't mean that your designs should be copies of other pieces out there, but rather, to ensure that some elements of your design will make your viewer feel at ease with what you made. Keeping your design both creative and making it familiar for people is not an easy task, but it is doable. Don't be afraid to experiment and see what works best for you.
Another important rule when it comes to design is to keep all the elements consistent with the style you choose. Even one photography that does not fit the rest can spoil the whole effect of a given piece of work. Make sure that all the images are kept in the same theme and that they correspond with the fonts and background colours. Also when choosing more than one pictures, you should make sure they all have similar lighting conditions so that they won't look too different from each other.