How to easily make a classic glossy and colorful web button in Adobe Photoshop in just a few steps.

1.
I started out with a 50 percent gray background layer and an empty layer to work on.
With the rectangular selection tool drag a selection that will make up the base shape of your object.
Go to select -> modify -> smooth and smooth the selection about 20.

2.
Make a custom gradient with the gradient tool as in the first image below.
With the gradient tool drag inside the selection to make it look like the second image below.

3.
In the layers panel make an new empty layer, click the first shape layer while holding down ctrl to load the shape selection, then go to edit -> stroke and in the new empty layer make a stroke about 5 px thick.

4.
Go to filter -> blur -> gaussian blur and blur it about 2 to soften the edges.

5.
Place the stroke layer above the shape layer and right click it in the layers panel, choose merge down.

6.
Make a new layer above the shape, and name it reflection. Hold down ctrl and click the shape layer to load the selection.
With the elliptical selection tool and selection mode called intersect with selection, selected drag as shown in the image below.

7.
Make a new gradient, going from white color to transparent, and drag it in the selection so your image should look like the one below. You may bring the reflection layers opacity down a bit, or give it a gaussian blur at about 2-3.

8.
Now double click the shape layer in the layers panel to get to the layers style panel and give it settings as below.

And you are done, now make your content in between the shape and reflection layers. I just typed in some text and used one of the default custom shapes in Adobe Photoshop.