With your layer style complete, open the Layer Style dialog window. Then click the New Style button on the very right. This will bring up a dialog box where you can enter a name for the style that you want to save.
At the bottom of the box, you’ll see two options that Photoshop usually pre-selects as needed. The first option, Include Layer Effects, allows you to decide whether you want to save the individual effects, such as Drop Shadow, Stroke, etc. Obviously, you want to keep it checked, as you want to save the effects used for the layer style.
The second option, Include Layer Blending Options, is only important if you made changes to the blending options of the layer, such as setting the blending mode to Overlay or Soft Light, or reducing Opacity or Flow of the layer. If you want to apply those changes, too, every time you use the style, then make sure to tick this option.
→ How To Use Blending Modes In Photoshop – (With Blend Modes Cheat Sheet!)
Once you’re ready to save your style, just hit OK and the layer style will appear in the Styles Palette. From there, you can select and apply it again whenever you wish.