I have never really mastered the art of easily
printing photographs taken with a didgital camera. For a start, the glossy photo paper seems to come in 6x4 - my digital camera does not frame the photograph in that ratio. I have a very capable HP Deskjet 5150 printer and use the hpijs driver.
I'll tell you what I currently do, you can have a good laugh and then tell me the easy way
I open the photo in the GIMP and use the crop/resize option to get my photo to fit on 6x4 paper. After saving I open the photo in flphoto (I use this for getting the pictures off the camera in the first place) and use the simple printing options available there. I have tried printing from other applications but cannot seem to get the printer to understand what I am doing eg. it might think the paper is A4 and I get a corner of the photo on my 6x4 paper or the colour balance / saturation is all over the place. You might ask "why not print from the GIMP?". Well there's a subject in itself. Again not easy