Here is the final result
Step 1 Create Envelope Shape Components
Because we want our icon to be a vectorial icon, we will only work with the Pen Tool,the Rectangle Tool, Custom Shape Tool, etc. The envelope has three initial layers as shown in the image below. Pick the Pen Tool and start by creating this shapes in three different layers: Envelope 1, Envelope 2, Envelope 3. The color is not important because we will change it in the next steps.
Step 2 Add Color Gradient to The Envelope Layers
Put all the pieces of the envelope in place like shown in the image. Open the Layer Style window and let's add style to all the three layers created in the previous step. Layer Style for Envelope 1 Layer. I will add Inner Glow and Gradient Overlay. Add Inner Glow, color of the glow #ffffbe, blend mode - screen, opacity 75% and size 4. Add Gradient Overlay, blend mode - normal, opacity 100%, style linear, angle 90 degrees. For the gradient use the following settings: color #aca99c, location 0% and color #f2f0eb, location 100% . Layer Style for Envelope 2 Layer. For this layer I will add Drop Shadow, Inner Glow and Gradient Overlay. Add Drop Shadow, blend mode Multiply, opacity 10%. Choose black color. For the angle of the shadow, first uncheck Use Global Light and set the angle to -90 degrees. If "Use Global Light" setting is unchecked means that the angle of the shadow will apply only to this layer and not to all the layers in your file. Set the distance and size to 2 px. Add Inner Glow. The settings are similar with the settings from Envelope 1 Layer. Add Gradient Overlay, blend mode - normal, opacity 100%, style linear, angle 0 degrees. For the gradient use the following settings: color #e9e6e3, location 0%, 50% and 100% and color #e1dfdc, location 20% and location 80%. Layer Style for Envelope 3 Layer. For this layer I will add Drop Shadow, Inner Glow and Gradient Overlay, similar to the settings of the previous layer. So here are the settings for the Drop Shadow: blend mode Multiply, opacity 10%. Choose black color. For the angle of the shadw, uncheck again Use Global Light and set the angle to -90 degrees. Set the distance and size to 2 px. Settings for Inner Glow Settings for Gradient Overlay: color #d4d3cf location 0% and color #f4f2ee location 100%.
Step 3 Create Envelope Details
I want to add some details on the bottom area of the envelope. For that I will use Custom Shapes. Pick from the list a basic shape that comes with the Photoshop CS4, called Tile2. Create two layers with this custom shape, one with the color #c73c3c and the other with color #138299 like in the image: Now a simple trick that some of you may not know is adding a mask to these layers. With the Rectangular Marquee Tool (M) make a selection like in the image: Return to the Red Lines Layer and press the Add Layer Mask button as shown in the image below: Do the same for the Blue Lines Layer. And the result so far looks like this:
Step 4 Create The Heart Icon
I will now draw a simple heart shape available also found in the Custom Shapes list, color #eb2929. Open the Layer Style Window and add Inner Glow and Stroke. For the Inner Glow the color is #bc1213. Add Stroke, size 4 px, color #ae0808.
Step 5 Create 3D Effect
Duplicate the heart layer and place it below the initial layer. Move it up like shown in the image. The color for this new heart shape is #eb2929. For these layer I will add drop shadow, inner shadow, inner glow and bevel and emboss effects. You can see the settings in the image below, I will just tell you what colors to use for every effect: drop shadow color #000000, inner shadow color #af0909, inner glow color #e71a1a. With Bevel and Emboss I will add the 3d effect and also a glossy effect. You can see the settings below; just make sure to uncheck the "Use Global Light" and to change the Gloss Contour to Cone Inverted. The colors used are white for the highlight and #c61a1a for the shadow mode. This is how your heart icon looks like:
Step 6 The Result of Valentine Love Letter
As a final touch add a nice text "Love u!" is always a classic text that almost never fails! I have used Amienne font. Another thing to do is to add a nice reflection. So group all the layers into a group, duplicate the group, convert it into a Smart Object. Now flip the smart object vertical. Make a selection, again with the Rectangular Marquee Tool, this time use Feather 20 instead of 0 px. And add a layer mask to the smart object and that is all. I hope this tutorial was useful for you! So this is the Valentine Love Letter, an envelope with a red heart inside!!!! Like this icon and don't have time to create it, you can download for free the Valentine Icon Set!