These links are from HONGKIAT.com  http://www.hongkiat.com/blog/40-cool-abstract-and-background-photoshop-tutorials/

• Abstract Signature
  Learn how to create a detailed signature using several filters and effects.
  
  
  
• Chroma Wallpapers
  How to create a energetic, vibrant, colorful wallpaper
  
  
  
• Windows Vista Aurora Effect
  How to create the Vista aurora effects in Photoshop.
  
  
  
• Abstract Walkthrough
  
  
  
• Luminescent Lines
  This technique is fairly simple and is a great way to create an abstract wallpaper or looks good integrated into another image.
  
  
  
• Abstract Background of Colored Bars
  Short but attractive way to create a graphic for backgrounds, wallpapers, greeting cards, designs, and all that other good stuff.
  
  
  
• Leopard Aurora Borealis
  Not exactly the Mac OSX Leopard aurora wallpaper, but great effects to create something similar.
  
  
  
• Brilliant Light Streaks Simple technique for creating brilliant light streaks which can be used in different ways to add motion and brightness to your designs.
  
  
  
• Space Lighting effects
  How to create a space scene with some nice Lighting Effects in 10 Steps.
  
  
  
• Calculations And Colorization
  How to create an Alpha Channel using the Calculations dialog and we’ll use it to get a really great abstract photo effect.
  
  
  
• Abstract image tutorial Create a beautiful and extraordinary effect with some simple steps.
  
  
  
• Cool abstract background
  Create abstract background from bubbles and waves.
  
  
  
• Abstract Light Rays
  
  
  
• Yet another abstract signature
  
  
  
• Abstract Summer Illustration
  Learn to create an illustration picturing the summer.
  
  
  
• Swoshy lines
  How to make an abstract ribbon-like effect using only Adobe Photoshop.
  
  
  
• Abstract Energy Lines
  How to create some energetic lines you can use to create more lively digital creations.
  
  
  
• Easy Abstract Photoshop Tutorial
  How to create a very simple abstract shape using a few brushes and effects.
  
  
  
• The lightning effect
  
  
  
• Intense Solar Flare (Filter) Effect
  
  
  
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  Abstract Art Piece: "Lonium"
  In this Photoshop tutorial we’ll be walking through the process of making an abstract artwork, using abstract 3D renders, textures, and more.
  
  
  
  
• Light Rays
  Create a fantastic light ray background texture
  
  
  
• Abstract Background
  
  
  
• The OS X Wallpaper
  Learn to create the iconic wallpaper using effects, gradients, masks and blurring.
  
  
  
• Digital Art Piece
  
  
  
• Grungy Metal Texture
  How to make some grungy metal with a star
  
  
  
• Signature Backgrounds
  
  
  
• Abstract Airbrushing
  
  
  
• Wallpaper Effect
  This tutorial walks you through steps in creating a warped effect that you can use to create artistic and profressional background andwallpapers.
  
  
  
• Trendy Background Textures
  Simple technique using brush strokes for making some trendy background
  
  
  
• Digital Star Effect
  
  
  
• Stripy Abstract Wallpaper
  Simple effect that can come in really handy.
  
  
  
• Magic light streak wallpaper in photoshop
  
  
  
• Mac-type background
  This tutorial is about making a "mac" style background.
  
  
  
• Colourful swirl
  
  
  
• Colorful Tornado
  
  
  
• Firey Explosion
  Spice up your space art with this explosive tutorial
  
  
  
• Abstract Artsy Background
  
  

• Abstract Lighting Effects in Photoshop

•  Create a Simple Vibrant Light Effect in Photoshop

• Creating Awesome Retro in Photoshop
  

• Create a Super Abstract Lines Background

• Create a Magical Rainbow Color Flame in Photoshop