Occasionally I want to add or subtract more clarity, contrast, or some other setting to or from the whole photo than the Lightroom Basic panel slider will allow. At this point I often turn to the adjustment brush or graduated filter. They are intended for making local changes to a photo, but you can also apply them to the whole photo. They allow you to use the following settings:
If, for example, I need more than 100 of clarity on the whole photo, I would set the Basics panel slider to 100, and then using the adjustment brush or graduated filter, I would add more.