The image(s) can set the overall feel to whatever you are creating and sometimes take the reins altogether depending on where or how you use them. Often, in fact, the majority of magazines use full, or half page spreads which is, as it would suggest either a full or half page with just an image on. Images are just more interesting to the human eye so it would make sense to find high-quality pictures and use them as often as possible (Don't go over the top though!)
The colours in the image affect what the shades of other things can be set as, for example, if you have a dark image like there is below you can't have dark coloured text as the visibility will be poor. Lowering the opacity can help out in some situations.
Graphics that you try to piece together will have to tend to the imagery as well. Again if you have a dark themed image, you most likely won't be splattering rainbows and ponies on it. The basic point I'm trying to make is that imagery does take hold of the creative design quite a significant amount.
As much as the above sound like handicaps to your work, if you look at it in the right way imagery gives you the coordinates to a great design and directs the whole process so just use your creativity to make the design flow. I see it as everything compliments each other if you go the right way about it. It's usually the colours within the images that have the biggest impact on everything.
Thanks for reading this week's "How to, in graphic design" blog