Willpower recovers naturally, after each conversation, you will recover some willpower depending on how well you are doing. Emerging victorious from a confrontation will allow you to regain more Willpower
Another way is by using consumable items that you can find lying around the world. Items like Polaroid photos and business cards will also allow you to recover Willpower.
Each character has items they feel connected to, and finding them in a chapter will allow you to use them from your inventory to restore your willpower.
Now that you know how to regain Willpower in Vampire The Masquerade, and you've realized how easy it is, we hope you can always have this stat at a good level, just remember to keep an eye out for the blue diamonds in the upper left corner of the screen.