How I created my 'valentines day gerbera with a heart of chocolate' image. If you don't have Adobe Photoshop you can download it and try it for free for 30 days.
I photographed the gerbera I purchased yesterday against the black armchair. I merged a photo of the chocolate heart (red) into the centre of the gerbera daisy and added a black background.
The final version, available for download from fotolia.com