As an avid macro photographer I really try to follow the rules, recomendations, or accepted guidelines to create the best photographs possible. My macro lens is a Canon 180mm f3.5 L series lens. It is very heavy, built like a tank, and when used properly, will give you amazing colors and detail. Generally I like to add my 1.4 extender to push the focal length to 252mm. This allows me to have frame filling compositions on small subjects without having to get nearly as close as you would have to with a short focal length macro lens. The longer focal length also does a much better job of creating the beautiful bokeh (blurred backgrounds) when there is seperation between you subject and the background.
Eastern Tiger Swallowtail on Compass Plant Flowers
With my macro setup, it is usually mandatory that I use a tripod. Normally I am shooting early in the morning or late in the evening when the light is low and soft. The drawback is I end up shooting at very slow shutter speeds. Also at these times there is less chance of a breeze to create movement. So generally as long as your subject is stationary, you can get some really sharp detail in your images. I use a cable release for the shutter, and I also use mirror lockup to further reduce vibrations and create the sharpest shot possible. I will shoot the subject and vary the f stop setting to try and keep my subject sharp but further blur the background.
Gray Hairstreak Butterfly
Many short focal length macro lenses (50-100mm) are light weight and give you a much better chance of getting off the tripod and getting some really good hand held macro shots. All the camera manufacturers have a variety of macro lenses in their lineup, and all the after market lens makers such as Sigma, Tokina, and Tamron do to. I am not going to give advice on them as everyone has differant needs in a macro lens. My choice was based on wanting the very best lens available that would give me great colors, bokeh, and razor sharp detail. The trade off is it is heavy, and not really good for doing hand held macro work. It is slow focusing in auto mode, but most macro lenses are. If you are doing precision macro you are generally manually focusing anyway.
Spicebush Swallowtail Butterfly on a native Thistle Flower