Step 7: Add A Solid Color Fill Layer

With our guides now in place, let's begin creating our "starburst" background effect. We're going to create the effect in a way that will make it easy for us to change the colors any time we want, so let's add a Solid Color Fill layer which will serve as the background color for the effect. Click on the New Fill Or Adjustment Layer icon at the bottom of the Layers palette:

Then select Solid Color from the top of the list that appears:

Step 8: Choose A Color For The Background

This will bring up Photoshop's Color Picker. Choose a color to use for the background of the effect. I think I'll choose a light yellow. It doesn't really matter which color you choose here since you can easily change it later, so pick whichever color you want for now:

Click OK when you're done to exit out of the Color Picker. You'll see the color you chose now filling your entire document:

If we look in our Layers palette, we can see that we now have two layers - the Background layer on the bottom and our newly added Solid Color fill layer, named "Color Fill 1", sitting above it:

Step 9: Select The Polygon Tool

Next, we need to draw a simple triangle, and the easiest way to draw a triangle in Photoshop is by using the Polygon Tool. By default, the Polygon Tool is hiding behind the Rectangle Tool in the Tools palette, so click on the Rectangle Tool, then hold your mouse button down for a second or two. A fly-out menu will appear showing you the other tools that are available. Click on the Polygon Tool to select it:

Step 10: Set The Number Of Sides For The Polygon Tool To 3

A triangle, as everyone knows, has 3 sides, so we need to tell Photoshop that we want to draw a 3-sided polygon. With the Polygon Tool selected, look up in the Options Bar at the top of the screen. You'll see a Sides option that is set to 5 by default. Change the number of sides to 3:

Step 11: Make Sure The Polygon Tool Is Set To Draw Shapes

As with all of Photoshop's shape tools, the Polygon Tool gives us three different options for how we use it. We can draw a vector shape, we can draw a path, and we can draw a pixel-based shape. We want to draw a vector shape, which will allow us to make our triangle any size we want without any loss of image quality. To draw a vector shape, make sure the Shape option is selected in the Options Bar:

Step 12: Draw A Triangle

We're ready to draw our triangle. With the Polygon Tool selected, the number of sides set to 3 and the Shapes option selected in the Options Bar, click somewhere in the top left of your document and drag out a triangle. Any size will do for now. It doesn't really matter where you draw your triangle either, I'm just trying to keep us both on the same page since I'm drawing mine in the top left. You want to make sure that your triangle appears to be pointing downward. By that, I mean that the top side appears perfectly horizontal. The easiest way to do that is to hold down your Shift key as you drag out the triangle. This will force the triangle to snap to specific angles. Move your mouse left or right as you drag (with the Shift key held down) until the triangle snaps into the "pointing downward" position.

As you're dragging out the shape, your triangle will appear simply as an outline (also known as a "path"). When you release the mouse button, the triangle will appear filled with color. In my case, it's filled with black:

Don't worry about the color of your triangle for now. We can change it easily later.

Step 13: Select The Move Tool

Now that we have our triangle, we need to move it into position so that the bottom point is sitting at the exact center of the document. To move it, select the Move tool from the Tools palette, or press the letter V on your keyboard to access it with the shortcut:

Step 14: Move The Triangle Into The Center Of The Document

With the Move tool selected, click on the triangle in the document window and drag it into the center of the document so that the bottom point is touching the exact center (the spot where the two guides intersect). As soon as you get close to the center, the triangle will snap into place, and that's because we enabled the Snap To Guides option back in Step 4: