My "prize winner" was a macro shot of an Iceland Poppy bud opening,with a flash of the bright orange petals starting to show. In the background were a lot of backlit out of DOF poppie s open,same orange. The odd bristled detail of the but and the unique moment in the life cycle made for a rather different "flower" macro. The light that day was great,I'd scouted that garden and it was on the way to work. I'd decided to wait for a day when the light was especially nice. I got that. The out of focus field of poppies in the background,and Kodachrome's tendency to show a "depth" between warm (orange) and cool(green) because of emulsion layers gave that slide a freakish 3D effect. In the viewfinder I recall feeling certain I had a blue ribbon in the flowers category. To my surprise...it was better than that....it won Best Of Show at the Santa Cruz Co fair,which was also open to photographers from Monterey/Carmel,Pro + Amateur. I'd used a rather ordainary Asunama 100 on macro tubes and my Mamiya DTL 1000. Even then--pretty low budget stuff.
As a gardener and photographer,I tended to find macros of flowers a great way to explore color and composition. There's hundreds of kinds of flowers in hundreds of hues and none seem to be in a hurry to be elsewhere. You can learn a lot about the importance of lighting (natural) and DOF,bokeh,the balancing of crisp and soft focus,pastels and deep color. Were I teaching photography,I'd use Macro flower photos as a primary means of learning the core elements of what makes for a good picture.
A nice thing about macro and in particular,flowers is that there is no big hurry. You often can spend a half hour checking out the possible variants. Also....a vintage (low $) Mamiya with it's spot meter and handy M42 tubes and -or bellows can out-do a lot of the "Big $" fancy gear. thanks to ebay...now I have a bunch of cameras that in the 80"s I could only wish for....but the good old Mamiya would still be what I'd turn to for serious macro.
B+W Macro? It's a relatively limited format,with the information and aesthetics of color taken away,tone and texture have to carry the load. Something like the works of an old watch could make a nice 11x14 print in B + W. Weston did a famous shot of a Calla Lily,that was so perfectly lit that it was erotic more than botanical.
Scale? An early macro I did had a Gazania as the main subject,a rather complex and colorful flower with-in that shot-a dark background. Blown up to a 2 ft x 3 ft print it became a prety impressive shot. Likewise,when you blow up a honeybee to the size of a house cat...it has some impact,it's a common thing seen in a much different way.
I recently saw a friend's pictures of Thailand,streets of Bankok,Temples at Angor Wat.....Oh My Gawd....
Another friend is an extreme skier and has shots of the Sierras off a simple digital point-shoot that I have to envy. Sometimes ya just can't GO where the great shot is. With Macro....there may be a great photo anywhere.