Bright and sunny day would be a nice time to shoot a beautiful sky, but if you are trying to expose a subject under shades or with their backs to the sun, you will more often than not get blown out or lack of sky details due to the dynamic range of a typical digital camera.
You can use Adobe Photoshop Lightroom to enhance the sky with the saturation slider, but your saturation settings will intensify the colors globally, and depending on the subject of the photograph, that might not be the best solution. With saturation, it is fairly easy to mrs with skin tones, and that is something that you would not want to mess with.
A good alternative is to use the blue luminance slider. It should pull some blues out of your image and as a result a more bolder and darker sky.
As with anything in Lightroom, you can make a preset out of it. My preset include 3 level of settings which you can use. As always, you can use the navigator to preview before you apply the said preset.
1) Navigate to your Lightroom presets folder. The easiest way to do this is to go to Lightroom’s preferences by clicking the Lightroom menu and choosing Preferences (PC: Edit > Preferences). Then choose the Presets tab and click the “Show Lightroom Presets Folder” button to open the Lightroom Folder.
2) Now go into the Lightroom Folder. Then go into the Develop Preset folder.
3) UNZIP the file you downloaded from the bottom of this post.
4) Copy and paste the “.lrtemplate” files into the Local Adjustment Presets folder.
5) Restart Lightroom
You can download my Deep Blue Sky Lightroom Preset here.