Tutorial courtesy of Photoshop In-Depth
Part I: Creating the Texture
In this short tutorial, I'm going to teach you how to create a forum signature image and a corresponding avatar image, all with Photoshop alone. For this tutorial, we are going to use a 500 x 100 dimension for the sig image, and a 150 x 150 dimension for the avatar. Additionally, I'm going to teach you how to create a cool liquid plasma effect that I picked up from Photoshop Techniques for your signature/avatar.
First, we are going to start with a big canvas in Photoshop. Create a new document which is 500px X 500px in dimension with 72dpi resolution. First, make sure your palette is reset by pressing D on the keyboard.
For the liquid effect, we are going to generate a high-contrast cloud texture. Go to Filter > Render > Clouds. You should have a generic-looking greyscale cloud effect. Then, go to Filter > Render > Difference Clouds to gain a bit of contrast in the image.
Keep repeating the filter by pressing Ctrl + F 5-6 times, until you get an image with decent contrast. Here's what mine looks like:
Then, create a duplicate of the current layer by dragging it to the "New Layer" icon in the Layers Palette. Alternatively, you can go to Layers > Duplicate Layer. On this new layer, run a Gaussian Blur filter through it with around 5px radius. Then, go to Edit > Fade Gaussian Blur and set the Blending Mode to "Screen".
Next, set the Blending Mode of the current layer (the duplicated one) to "Screen". Run it through a Chrome filter (Filter > Sketch > Chrome) with high smoothness and low detail. Then, do a 2px Gaussian Blur on it and immediately go to Edit > Fade Gaussian Blur. Set the Blending Mode to Screen again.
By now, you should have an image with a lot of highlights. Create a new Hue/Saturation adjustment layer and check the "Colorize" box. Then, drag the Hue slider to choose the colour of the liquid. Then, create a new layer above the Hue/Saturation adjustment layer and set its Blending Mode to Overlay. On this layer, paint in the shadows with a black colour. You want an even spread of highlights and shadows throughout the image.
Now, press Shift + Ctrl + E to merge all the layers together into one single layer. Then, go to Image > Adjustments > Levels. Drag the sliders so that you have a decent amount of dark shadows and less amount of highlight. Here is my image:
We're done with the texture. Let's transform this image into our avatar and sig file!
Before you proceed, please save your existing texture file!
Creating the Avatar Image
First, select the Crop Tool. Set the Width and Height to 150px in the Option Bar (it's just below the menu) and drag a square with it. Choose a region on your image where there is not too much details.
Double click the Background layer to make it into an editable layer. Then, double click again to activate the Layer Styles dialogue box. Then, go to the Inner Glow section and choose a white colour. Set the blending mode to Colour Dodge. You'll end up with something like this:
Finally, type your name on a new layer in white colour and position it over a dark region so that it is visible.
Creating the Signature Image
Let's revert to the original 500 x 500 file. Select the crop tool again and this time enter width: 500px and height: 100px. Crop a section of the image that looks best to you. Overall, this image is rather dark, especially with the amount of detail in there. So, we will brighten up the image a bit.
First, duplicate the Background layer and set the new layer's Blending Mode to screen. Then, do a 2px Gaussian Blur. This should brighten up the overall image.
Then, add in your signature line and you're done!
Obviously, the greater part of the tutorial focuses on creating the texture as it is the focus of the whole image. Besides following exactly what the instructions say, you can try and add in filter effects of your own to obtain new images! Just keep experimenting with layers, blending modes and the stock filters in Photoshop.