Layer Styles work in exactly the same way as Text Styles. The only difference is that they work with shape layers, while Text Styles work with text layers.
Creating a text or layer style
To create a Layer Style, select a shape layer with styles applied, then click the Create button in the Appearance panel of the Inspector. Alternatively, open the Components View, click on the Layer Styles 
tab on the toolbar and then on the 
button. Creating, editing, and applying Layer Styles works the same way as Text Styles.
If your Layer Style has corners, you can choose whether to include them in the style or not. Corners are included by default in any new Layer Styles you create, but they’re disabled for existing ones.
How to create a Layer Style in Sketch.
Tip: You can include Layer Styles a part of a Library for sharing with others. Take a look at Library Styles for more details.
Applying Layer Styles
You can apply Layer Styles to almost anything — shapes, vectors, Frames, graphics, or groups. You can’t apply them directly to Symbol instances, but if the Symbol Source includes styles, you’ll be able to override them in the instance.
To apply a Layer Style, select the layer you want, then click the style button under the Appearance section in the Inspector. Choose the style you need and click to apply it.
Inserting a text or layer Style as a new layer
Inserting as a new layer with the Command Bar
Press S or click the Sketch icon in the toolbar to open the Command Bar and select Layer Styles to view all available styles from your Libraries and current document. Choose the style you want, press ⏎, and click on the Canvas to insert it as a new layer.
You can also double-click or click and drag a Layer Style from the Command Bar to insert it as a new layer.
Inserting as a new layer from the Components View
To insert a Layer Style or Text Style from the Components View, select the component you want to insert as a new layer and click on Insert Shape with Style or Insert Text with Styles in the Inspector.
Deleting a layer Style
To delete a Layer Style, switch to the Components View in the Mac app. Head to View > Components in the menu bar, or use the keyboard shortcut ctrl2. Then, click on the Layer Styles tab. Select the style you want to delete and press the backspace key.
