Texturing using the 'Texture paint' mode:
This tutorial will teach you how you use the 'Texture paint' mode, it is much quicker than making a texture in Gimp/Photoshop but generally will not give such a good result.
First open up your model (if you don't have one you can download mine from the last tutorial here
First split the edit window in half (spliting and joining areas explained in the first tutorial)
now set the window mode to 'UV/image editor'
you should have an area that looks like this:
now click 'image' > 'new image', call it whatever but make sure you add the .png suffix to the end or it will think it is a jpg, keep the rest of the settings the same, but change the colour to a dark grey.
The next step is to set it to set the other area to edit mode.
Now select all the vertexes (you can do this by pressing 'a').
You will need to unwrap your texture, you can do it manually but it will take you ages, it is much easier to go 'mesh' > 'UV Unwrap' > 'Smart UV project' (like below).
you should now see bits of your model in the image window, but you now need to link those bits to you image, so click the image icon and select your texture
You can close the image window if you want.
Now to start texturing it, set 'viewport shading' to textured, you should notice your model go the dark grey colour
set mode to texture paint, the lines on your model should disapear, if you want them back click the icon highlighted below, you also need to click the (+) symbol in the top right corner for texture paint options
your screen should now look like this:
Now it is completely up to you what you do, play around with the menu to change opacity and colour and just draw straight onto the model, please post your finished creations to the 'Show and Tell' thread.
In the texture window you should click "image > pack image" this means that the texture is saved in the .blend file (of course when you export it as an obj you also have to export the texture)