Looking for the above traits will often help to spot autopenned signatures but the key test is in fact to compare the signature to known autopen patterns.
With repeated use the a particular astronaut signature template would eventually wear out which meant in practice that each astronaut would need to have a new template made every few years. This means that most astronauts have more than one autopen pattern and some have many.
A signature should be compared with all the known autopen patterns and if it matches any then it is almost certainly an autopenned signature. Small variations in the execution due to the paper moving whilst the machine was working can occur (see below) so if most of the signature matches a pattern but there are small differences it is still most likely autopenned. If in doubt, you will need to refer to the traits listed above to help decide if it is real or not, or seek expert opinion (be aware that most celebrity/sports autograph experts are not specialists in astronaut signatures).
You can use the menus to view examples of known autopen patterns for most of the early astronauts (up to the Apollo years) as well as some examples of crew photos signed by autopen. Remember that these examples are not exhaustive, although if you find an autopen pattern that is not included please contact me and I will be glad to add it to the examples.