How to create a border-bottom on photoshop?

I mean i could use the line tool to make a line in the bottom of the button but is there any other way like when i create the button with the restangle tool to use the stroke over there and make the line on the bottom?





what i mean is this:-->

 

What you can use is a drop shadow then just change the angle, choke, color, and opacity. That will give you the desired effect you are looking for.

 

Or just duplicate that same rounded rectangle, position it 5-6px bellow the original one and change color.

 

Thanks guys both of your advices worked

 

Use drop shadow or make new layer and press Ctrl+A and then add stroke.