To elaborate, there are some powers that will affect Force-absent creatures. Any indirect power, as listed above, will affect them by necessity of not affecting them, but affecting a third party. Fabula could enhance her strength with Rage or Valor and then crack their skulls, and Shorn could pick up a speeder and crush them beneath it.
Targeted powers, like Force Grip and its derivatives, don't affect them anywhere close to the extent that they do to other beings. As an extension, lightning can affect them, but it won't burn them as much as most targets. They are entirely immune to any mental powers, and they can't be sensed normally either.
A special power was created by the Jedi to counter the Vong immunity to sensory powers. This would also theoretically allow the user to apply precognition to Yuuzhan Vong they were fighting, which would make defeating them much easier. However, Vongsense also requires the user to temporarily abandon all other Force abilities. It's all-or-nothing, but when your enemy is immune to 90% of everything you can do, it's generally worth it to have one something that can work rather than a whole lot of nothing.
And before people start complaining about the Vong being overpowered, they were created out of necessity for a non-Sith villain that could actually challenge the Jedi. Much like on Chaos, the Force users of the Legends universe had become so extremely powerful that conventional threats simply didn't bother them. They required other Force users in order to feel endangered at all. The Vong were created explicitly to counter the rising power of Jedi in canon at that point.
See also: Legacy, after the Vong, where the villain is once again the Sith. In order to challenge Force users, the writers required either more Force users, or an entity specialized in hard-countering everything Force users were about.