The best way to do this is the Skill Tree.
Go to the CEO's Office and check out the right side button bar.
By accessing the Skill Tree, you will be able to invest your earned Skill Points into either Clicker or Idle skills. These will help increase your revenue. You gain 1 Skill Point for each company you manage to sell.

We recommend you invest your points wisely.
But rest assured, if you want to redistribute your Skill points in a different way, you can always use the reset function within the menu.