Best way to get to Tokyo

I am looking to move to Tokyo in March 2013 and need advice on the best option for me to do this.

Im 26, I have 10 year experience as a Graphic Designer but no degree.

I have only recently begun learning japanese but doubt I will be at conversational level by the time I move, let alone a business level.

I have been looking at TEFL and this seems like a viable option - but will the visa i get for teaching english also allow me to do freelance design?

also what other considerations should I be aware of?

I have been looking at TEFL and this seems like a viable option

Unfortunately, this is not really an option as you will not qualify for a work visa to teach. You're 10 years in graphic design might qualify you for a visa, but the scope will only cover jobs in the graphic design field.

but will the visa i get for teaching english also allow me to do freelance design?

No, not legally.

also what other considerations should I be aware of?

Have you considered the working holiday visa? It would allow you to live and work in Japan for a year, but after that you're back to square one in terms of getting a work visa.

Could you explain why I would not qualify for a work visa with TEFL?

For a work visa, you need to have either (1) a bachelor's degree or (2) several or more years of relevant work experience.

Since you do not have (1), the only chance you have is with (2). As it says "relevant," with your ten years of graphic design work experience, you have a chance to be granted a work visa so that you can work for an employer in THAT field, namely, graphic design.
There is no one "general work visa" that allows you to do any work in any field.

Your best bet would be to go for a working holiday visa, which is available only to nationals of several countries, and teach English in Japan for up to a year, or get a bachelor's degree.