Hello Jimmy and welcome.
Also, I have a question: when should I use the paper strip method and when should I use the pulp method? So far I've only used the strip method. Is there situations where the other method is better? Also, when I use the pulp method, do I put the pulp on some kind of armature? Or do I just mold it w/ nothing underneath?

You're probably best sticking (!?) to the layer or laminating technique first until you're familiar with it.  It should be ideal for your departed cat.  Read the various articles and tutorials and make sure your paste is reasonably thick (double cream consistency) and use only a thin smear on the paper.  Basically, don't get your paper any wetter than you absolutely have to.
For the pulp, look carefully at Martin Favreau's article and the different types.  If you combine layering and pulp, be aware that the moisture of the pulp can be absorbed into the laminate and weaken it to a point of collapse.
Generally, you would always use some form of armature (which can be any one of a very wide range of things) to take up space as well as to give a firm inner shape/skeleton.

I hope that is of a little help.  You can always come back with further questions and there are quite a number of people who can help with answers.