First, you have to experience the world.
Second, you have to understand the world

If you have experienced the world and understood the world, then
You may wish to explain the world to others.

To explain the world to others, you must gather some people and speak to them.

The people you gather may find your explanations helpful. Or... not.

Philosophy is the activity of thinking, reading, or writing about the nature of things, or unanswerable questions. Its methods are what it takes: for example clarity of expression, valid and sound argumentation, curiosoty, intellectual honesty, insight, regard for truth and so on.

What are the methods for creating a new philosophy? — hiroko

A new [system of] philosophy is created by practising philosophy.

So, how is philosophy practised?

Generally, by interpreting a significant experience and/or modelling a domain. This results in the acquisition or modification of knowledge.

Specifically, by:
1) Problem Definition
2) Solution Strategy Implementation
3) Perception or Imagination
4) Observation or Introspection
5) Interpretation or Modelling
6) Argumentation
7) Constructive Criticism

1. Think the unthinkable.
2. Make sense of the resulting nonsense.
3. Write a detailed account of exactly why every other philosopher in history got it all wrong.

1 is the tricky bit, despite folks thinking they're doing it all the time. Because it encapsulates the contradiction in your title. To have a method is to be doing the same thing that has been done before; but to be creative is to come up with something new. It is unwise to expect that doing the same thing will result in something new.

To have a method is to be doing the same thing that has been done before; but to be creative is to come up with something new. It is unwise to expect that doing the same thing will result in something new. — unenlightened

So the repetitive application of one method is incapable of producing unique results? Sounds like a new philosophy to me. I'm looking forward to the detailed account.

No, nothing new here. Interesting slide from creativity to uniqueness. Every snowflake is unique, but snow is nothing new.

Each object is unique, but ideas seem to rely on each other.

Look at that, you're already unique, and original. So just be yourself!

I say use a timeless, tried and true method to come up with something brand new every time.