Design a Grinning Smiley

Start by creating a circle using elliptical shape tool.

Double click the layer to open layer style window. Apply layer style with the settings shown.

Ctrl+Click the layer thumbnail to get the selection. From select menu apply modify>>contract. Contract the selection by 2 pixels.

Create a new layer and apply a black to white gradient in linear mode. Change the layer mode to soft light.

Create an elliptical selection using elliptical marquee tool. Create a new layer and fill it with black to white linear gradient.

Change the layer mode to screen. Create an ellipse using elliptical shape tool. Press Ctrl+T. Right click the layer and select warp. Adjust nodes to get the shape as shown.

Enable subtract form shape area form the top bar.

Create another ellipse using elliptical shape tool.

Double click the layer to open layer style window. Apply layer style with the settings shown.

Use the same techniques mentioned above to create a glossy look.

Create an ellipse for the eye ball using elliptical shape tool. Again subtract the shape from the bottom as we did for the bigger shape.

Double click the layer to open layer style window. Apply layer style with the settings shown.

With gradient overlay panel open drag the gradient in the eye ball to show the glint in the eye as shown in the image below.

Similarly create the other eye.

Create an ellipse for the nose and make it glossy.

Create some rounded rectangles for the teeth. Select and merge all the rounded rectangle layers.

Press Ctrl+T. Right click the layer and select warp. Adjust nodes to get the shape as shown.

Double click the layer to open layer style window. Apply layer style with the settings shown.

Press Ctrl+Alt+G to create a clipping mask.

Similarly create lower teeth.