The scene is created with blender 2.76 but it should work just fine with other versions.
The first cube is rendered with the standard settings in a fresh file. I just changed the cube's colour to green.
The other two cubes are rendered with the changes described here.
Anti-Aliasing (blue box in screenshot) is used on the left cube, the right one is rendered without it.
I mostly render things without AA but maybe its worth trying for some items, for example cloth or fabric. If you don't use AA, an outline should be added after rendering for better looks.
You can change to orthographic view by pressing NUM 5 in the 3D view window. The effect will explain itself immediately
The rotation is changed to 45°, 0°, 45° (red box in the screenshot)
Camera type is set to "Orthographic" (you can access the camera settings in the yellow box)
With the orthographic scale you can adjust the size of your objects in the final render without having to "really" scale them.
There are two lights, both set to "Hemi" to ensure that lighting is independent from the objects position.
On of the lights is just facing down. It's set to "Energy: 0.5" and represents the light scattered by the atmosphere.
The other one is oriented 0°, 45°, 225°, this is our sun
(Between yellow and blue box in the screenshot)
The resolution for rendering is set to 200 by 200. In my experience this fits most single items.
The Percentage scale is set to 100%. I am not even sure what it does exactly, but 100% just sounds better to me than 50%
The aspect ratio! This distorts the rendered image and is crucial for the unusual UO perspective. We want a distortion factor of square root of 2 (1.414) for the x-axis.
In the pink box you can switch layers on and off.
Shift+Click for selecting multiple layers.
Move an item to another layer with selecting it and pressing m to move it to another layer.
The camera and the lights are on the second layer for a free view while editing the object. There is also a black plane acting as a background for rendering with anti-aliasing.
Finally, some basic commands for blender. This does not replace a proper tutorial of course, but those are nice to know when starting to work with blender.
rotate view: press mousewheel
select items: right-click
move items (grab): g
scale items: s
rotate items: r
You can restrain the last three commands to one ore more axes by pressing (x/y/z) you can also exclude one ore more axes with Shift+(x/y/z)
Rotation around x-axis: r, x
scaling in x and y (exclude z): r, Shift+z
(confirm with return key)
You can also enter an exact number, by typing it after pressing the key for the command.
This doubles the selected items size: s, 2
(And of course you can combine these: s, x, 2 for example)
To switch between object-mode and edit-mode press TAB.
I hope this helps some people already working with blender and/or motivates others to start
If you have questions about this tutorial or on any other blender-related topic, just ask! (And i will try to answer it )