I recently came across the portfolio website of Patrik Hübner and noticed a great tutorials section with design tutorials in PDF format. He currently has two issues posted on the site and it looks like there will be a new issue every month. Below is a sneak peak of what you will find in the tutorials:

Issue 3 – Vectors With a Lacing of 3D
In this tutorial you will learn how to:
- Create vector shapes in both a 2D and 3D-environment
- Discover how to unleash your vectors into the third dimension
- Create useful and great looking textures
- Create and scatter a custom brush
- Modify vectors via layer masks
- Use shapes with alternating opacity to create great effects
- Texturize your vectors in 3D
DOWNLOAD ISSUE 3
Issue 2 – Digital Illustration With Adobe Photoshop
In this tutorial you will learn how to:
- Create and colorize textured backgrounds
- Create a custom brush-style using Adobe Photoshop
- Discover how to employ the Smudge-Tool and Displace-Filter
- Create and modify custom vector shapes
- Optimize color-curves and adjust colors using adjustment layers
DOWNLOAD ISSUE 2