Altium: Assigning testpoints
Assuming you don't have access to the Altium forums. So here's what I posted there:

You basically have two options:

1: Setup your rules and decide how your testpoints will look like (you need to setup two distinct rules; Testpoint Style and Testpoint Usage): Then you can use the testpoint manager to assign testpoints automatically to Vias or Pads, basically stuff that is already there and doesn't have soldermask on top).

Although this would be the fastest approach, in the past, we've had difficulties with this approach since many of our machines during production need to actually have a "component" handle to be able to handle these testpoints. Even if we got all testpoints via the testpoint report we didn't know which net was assigned. Also, we wanted to have full control over testpoint placement. Therefore, we're doing it by hand in the following way:

2: Use a component (e.g. a small circle with a dummy pin) on your schematic, as a footprint create a dummy footprint with a pad, sized 0.3mm (or whatever size you need; also make sure to remove paste) and assign that footprint to your schematic symbol. The "Pad" will make sure that there is no solder mask at that specific position.

I attached two example files for #2 to this post.  

I would highly recommend using #2 for your designs, yet this opinion is based on our experiences at our company :-)

I uploaded example files for approach #2 here: http://1drv.ms/1MQwcg6.

In case you do have access, this is the thread: https://forum.live.altium.com/posts/211923