Glass Button Photoshop

0. Create new document.

1. From tools select foreground color to dark grey (444343).

2. Click on Paint Bucket Tool (G), from tools and apply color by clicking on white background.

Add an Outline to a Button

0. Create new document.

1. Select Rounded Rectangle Tool (U) and create button.

2. Select the Layer (Rounded Rectangle 1).

3. Click on fx button at the bottom of the Layers panel.

4 Ways to add stroke

Adding Stroke to already created shape

Option 1: from menu bar click Layer, than Layer Style and click on Stroke.

Option 2: in Layer Panel click fx buttom and than Stroke. 

Option 3: Double click on layer you want to add stroke. Be sure not to click on name, click on image (square). On left side, from Styles, click Stroke.