I've been asked where I get so many different flowers to photograph. I thought I'd share some tips on the subject and I hope others will share theirs.
Locations - Not everyone lives in a warm climate, but that doesn't mean you can't get some great shots. Look in your area to see if there are any plant nurseries, hot houses, green houses, botanical gardens, etc. A lot of my shots come from Lowe's and Wal-Mart. If you ask the manager of the store, most of the time they are not only happy to let you take pictures of their plants, some will even help you find the best ones or hold them up for you to get a great shot. I have agreements with several local places. They let me take photos and I give them a few of the files for their advertising. One even calls me everytime they get in a new or unusual flower. I also sometimes buy them from florist shops like the daisies shown here. I noticed how crisp and clear the day was, and loved how blue the sky was, so I went to the florist and bought one stem of daisies, held them up and voila... A pretty shot.
Fixing the Flowers - Sometimes there is pollen on the petals or maybe dirt on the leaves. I use a soft paintbrush to remove what I don't want. Also, you may have a leaf that's not quite in the right spot. Some green florists tape or a discretely placed pin can help with that. Just make sure that if it's not your plant that you get permission. The florist tape will most likely cause little to no damage. If you want a wet look to the flower, you can use a spray bottle, but I prefer a watering can. You get larger, more natural looking droplets without overdoing it.
Composition - Rule of thirds, rule of thirds, rule of thirds. Nothing is worse than that dead center shot of a flower set dead center on the photo. Also, leave room on the sides for future manipulation if possible. Let the light flow from left to right (same way your eyes read a book).
Backgrounds - Be careful and make sure you don't have a busy background where possible. Most flowers are very detailed and you don't want to take away from that with a lot of detail in the background. A clear blue sky makes a great background.
I hope that helps someone. Now, add your own suggestions to help me! :)