I'm based in Japan. It seems like most other teachers like me are here for the onsens and green tea, but I've been flirting with teaching Phonics in school for the past 2 years. Everything I know about Phonics, is self-taught.
I've received the okay from all my JHS and elementary schools to focus on teaching the alphabet and Phonics. This is especially surprising because I work in the public sector. My elementary schools don't really care as long as I keep English "fun."
Anyways, with much skeptisism around me from other teachers like me and from other JTEs in JHS, I started this year soley teaching Phonics in JHS and the alphabet from 3rd grade in elementary school.
In ES, teachers start teaching romaji in the 4th grade. While this might seem like a minute point, I want to teach the kids the REAL names of the alphabet, instead of its butchered katakana equivolent. While teaching the names of the 26 different letters of the alphabet doesn't sound like Phonics, I've really studied how Japanese say the alphabet using katakana-English. Then, when I teach how to say the letters properly, I show the students the differences. They seem to be absolutely amazed. For example, I the teach the 'F and V' as 'biting' letters. Meaning, when the student says those letters, they must either bite their bottom lip, instead of a mere blow like the katakana-English produces, at the beginning or ending of saying the letter. Another example, is the 'M and N.' In katakana, when you say the M, the mouth starts from an open position, closes and then re-opens, but when saying M using proper English, the mouth starts from the open position and only closes. Once they are able to read letters, I will move to the sounds, but for the time being, I'm only teaching the alphabet. My theory is that the students are learning English words in their everyday life, so if they come across an English they know, I'm trying to give them the tools to read them and pronounce them correctly.
I've also started a homework system, which really concerned the teachers because of the "homework" stigma having negative connotations. I told them not only is the homework fun, but they are just perpetuating the ongoing stigma that homework is something that shouldn't be fun. The great thing about this homework is that I make it optional, so if the kid doesn't want to do it, they don't have to. But, if they do, they can receive points for their point cards.

I've been teaching this new method for about 3 months now and see a class on average once every 2 weeks. To date, about 95% of the students are doing the homework, 2nd graders are writing their names in romaji (granted, they are butchering the names but their trying), 3rd graders are forming a firm grasp of the non-sequential alphabet (I rarely put the alphabet in order from A-Z), the students are having fun, and I've caught a couple of the teachers taking notes.

Also, I've discovered the children are starving for knowledge. I handed out worksheets to 4th-6th grade students. The worksheets were mere tracings of their names in romaji. Evidentially, one student was so motivated to study English, unbeknownst to me, she asked her teacher to make her some photocopies so she could practice some more. Over spring break, she practiced writing her name. At the beginning of the next class, she gave me 22 pages of her just writing her name. She wrote it 507 times. I was so impressed that I told her if she wrote her name 1,000 times, I would give her a present. Within two weeks, she had written her name 1,034 times. Now, two other students in the class are going for the 1,000 time benchmark. The dangerous thing is this catching like wildfire cuz' it might get a little expensive and time consuming. So, if anyone has any good ideas about cheap and fast presents that students absolutely love, I'm all ears.
In JHS, in the ALT classes, the students aren't even reading yet. For the last 3 months I have been teaching them sounds, with the JTE occassionally asking to substitute the Phonics class with a textbook class.
This plan will change in the future, as my knowledge about Phonics increases, but my first 7 lessons have gone like this:
Lesson 1: beginning sounds - BCDJKPTV
Lesson 2: ending sounds - FLMNRSXY
Lesson 3: a combination of lesson 1 and 2 to test to see if the students can differentiate between the two.
Lesson 4: voiceless sounds - CFHKPSTX
Lesson 5: voiced sounds - BDGJLMNRVWYZ
Lesson 6: once again, a combination of the two lessons.
Lesson 7: a big test of all 4 lessons.
Each lesson is not a class, but rather we work through them at the speed of the class. Each lesson comes with a worksheet that tests the students' comprehension. This style of teaching seems foreign to most of the teachers around me and every lesson comes with a degree of failure on my part about not blending Japanese culture correctly into the lessons, but I use the mistakes as points of reference to fix in the future. It almost brought a tear to my eye when a student didn't know how to spell a word and he was able to correctly spell it based upon it being sounded out phonetically.
I think the great thing about getting back to basics is that it shows the JTE that making mistakes are okay and encouraged because it promotes a healthy classroom environment. I'm sure we can all relate to wanting to cringe when we hear the English teacher speak in katakana, but teachers are starting to come around and realize that they don't need to be perfect. The only difference between them and their students is that they know the material better.
I think the greatest thing about teaching Phonics in Japan is that it keeps the creative part of your mind alive and resilient to the Japanese outside-the-box-thinking-borglike-assimilation.
Anyways, that's what I'm doing when it comes to teaching sounds in the classroom.