The availability of different skies has always been important to photographers. Even with transparency film (slides) sandwiching an attractive skyscape in the mount of a landscape was frequently performed to improve the scene.
In digital terms there is no need to sandwich, all we are required to do is select the dull existing sky with a magic wand tool, delete it and then drag over a much more interesting one.
If you start to look at your own images, like me, I guess you will find that many of them could do with a bit more oomph in the sky department. Maybe you have just accepted what was there
thinking there was not much you could do, but there is no excuse anymore. If you start to think about it the chances of hitting a landscape at the right time when everything is just right does not happen that often. It's always worse when you have to travel miles to get to the venue. You can't easily go back.
Why not start to take interesting images of skies wherever you are and save them in a separate folder on your computer.
Taking sky images is not that difficult to do. Set your ISO to 100 or 200 to minimise grain, attach a 12mm or longer wide-angle, bracket the exposures and lay the camera on the ground lens upward but make sure that you are out of the way so you or nearby buildings do not appear in the image.
If you include the sun you may need to switch to manual exposure mode and set the light levels yourself. Don't forget the rule of thirds for optimum positioning. There is no need usually to shoot raw, jpeg's are OK at the large, fine setting.
One of the most attractive skies can be the sunset. These do need a little more attention. Firstly I suggest that you bracket more extensively
to have a greater no of exposure variations as this influences the colour considerably. Also try shooting the sky in black and white and add a colour tone of your choice from the camera’s b/w menu as this can be very effective. Or shoot with a coloured graduated filter
in place to add extra emphasis to a particularly colour. Use levels and curves in Photoshop to enrich or de-saturate the colours to your own preferences.
Finally, why not experiment a little and make the sky the image itself.