Modern cameras and film make great photos easily. 
Much simpler than using the Graflex 4by5 view camera on the left. 

All experts have few basic guidelines which they follow.  If you have a 35mm camera; you can make great flower photos too; "guaranteed". Try these basic guidelines, or "rules of thumb." 

* No Super Bloopers: Like not having film or batteries in your camera. 

*  For only a few cents more, use the best film possible.  Slow film with a lower ASA rating number will be sharper and have better color saturation than the "faster" 400 films. A film speed of ASA-100 is good for enlagments up to 16 x 20. 

There are excellent films for slides or prints.  It is a matter of personal preference which kind you use. If you are going to take many photos and make just a few enlargements, slides (or transparencies) cost less.  On slide film, the final image is produced right in the film.  Slides retain their bright vivid colors for many years. Fugichrome-100 is a good slide film for flowers, as are several others

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Slides 
or 
Prints?

Flower photos will fool the enlarger into thinking that the photo is the wrong color and it will try to "correct" for this bright color. For instance, if you have a photo of a large yellow flower, the machine will add the opposite "blue" and make your photo much duller than it really is. There is no easy answer to this automated problem. Look closely at your prints and have the photo finisher print them again making manual corrections. A good color print film for flowers is Kodak's Ektar-100. 

By way of correcting exposure errors, color print film is more forgiving of our mistakes.  Prints are usually best for portraits and people and scan better on the average home scanner.  Prints can always be punched up in color saturation and contrast if necessary.

Use a normal focal length lens like the one that came with the camera. One that is too wide will let all the background clutter into the picture. 

An aperture setting of F-8 to F-11 is a good compromise for sharpness and depth-of-field (the distance in depth that the lens stays in focus). Look carefully to compose the best background. Distractions and shadows can ruin a great photo. Use colored posterboard or dark colored cloths to shade background distractions. 

Get in close so the flower fills up the whole picture without a lot of empty space? ...Macro, means that your camera will focus in close. If your lens is not macro, you can add "close up rings" to the accessory threads on the front of the lens. These come in different strengths, measured in diopters, like grandma's glasses. With a set of three "close up rings" in strengths of 1, 2, and 4 diopters you can get any magnification between 1 and 7 with different combinations of rings. This will help your lens focus right into the flower, which is more dramatic, especially when enlarged (real big). 

 Vertically oriented photos are usually best for things that grow "up." Also, verticals have more strength than the same horizontal photo. Have you ever seen a horizontal magazine cover?

Another way to reduce camera movement is by holding your breath, then holding the camera tight against your face with both hands.  Squeeze the shutter release steadily to the point where you don't even know when it is going off. 
Where tripods are not allowed, some photographers brace the camera against a beannie baby (oops, I meant bean bag). 

Should I photograph flowers on a cloudy day? Not necessarily, the sky is a filter that limits the quality of light. A bright sunny day with just a little haze or clouds to soften the shadows is best. The warm tones and low shadows in the morning or late afternoon add the most pleasing effects to most photos. Bring a spray bottle to "mist" the flower with droplets of water for that added touch of dew. 

Don't put anything dead center in your photo, it will produce a photo that looks lifeless like you shot it with that focusing target in the middle. Groupings of three make a good composition. 

Make sure all the lines and actions are moving in and around in your photo and not pointing out of the picture. Later on, a viewer's eye will follow those lines. Some excellent photographers visualize their future picture as it would look printed and framed on a wall.  They can see what they like and dislike before pressing the shutter release.

Making great photos of flowers takes some practice. With this naturally great subject though, you'll have colorful photos to enjoy all year long. "Guaranteed". Happy Shooting!