Are reflexive pronouns direct or indirect? Nope. In many dialects they have a strong tendency to be objects, but nothing about the pronouns themselves indicates whether they are direct, indirect or prepositional. That depends entirely on how they are related to whatever governs them.
I made myself a pizza.
"Myself" probably serves as the indirect object in this sentence.
The verb "made" is very flexible. It licenses several argument patterns. It can be simply transitive (direct object only), ditransitive (indirect and direct objects) or complexly transitive (direct object and object complement).
As it stands, the example above is ambiguous. It fits both the ditransitive and complexly transitive patterns. This allows two possible interpretations which can be paraphrased in these ways:
- I made a pizza for myself.
- I made myself into a pizza.
The former makes sense in a literal, real-world context. The latter might be appropriate as a metaphor or in a fantasy setting.
We cannot tell from the word alone whether it is an indirect or direct object. We need to know (or at least guess) which meaning underlies the sentence before we can determine the type of grammatical object that the word represents.
I made the pizza myself.
Again, there is an ambiguity. In this position, "myself" does not serve as an object. It might be an object complement, or it might be an adjunct*. Here are two possible ways to paraphrase this sentence:
- I used the pizza to represent myself. (A metaphoric use of "I made the pizza into myself")
- I personally made the pizza.
Just as before, we need something else to resolve the ambiguity before we know which grammatical role is filled by the word in question.
Theoretically, there is at least one more alternative available:
- I created myself for the pizza.
Offhand I can't think of what context would make that interpretation a sensible choice, but I also can't claim that it's grammatically impossible.
So, here are the answers to your questions:
Is the reflexive pronoun of "I made myself a pizza" a direct or indirect object?
Yep. It's very likely to be one of those, and more likely to be indirect in an everyday context.
Is the reflexive pronoun of "I made a pizza myself" a direct or indirect object?
Nah, probably not. The most likely meaning of that sentence uses "myself" to fill an adverbial role.
* It's possible that its use as an adjunct stems from an elided preposition: "I made the pizza [by] myself." Even if this is true, that wouldn't make "myself" into either a direct or indirect object. Under that interpretation, it is a prepositional object. It is still something that is not licensed by the verb.