I've been cooking adobo for almost a decade and only now do I honestly feel that there's little to no need for experimentation. Once I tried my uncle's adobo, I realized why my adobo always seemed off and I learned to trust that you don't need an extensive amount of ingredients to make something good. Lastly, mistakes are not always a bad thing.
My uncles method involved marinating the chicken in all the ingredients (bay leaves, soy sauce, pepper, garlic) except the vinegar for at least 20 minutes. He said to use a full bulb to 2 bulbs of garlic per kilo of chicken (2.2 lbs). The ratio generally is 1:1 for soy sauce to vinegar, but he had to dilute the vinegar since it's a lot stronger here in the US.
After the chicken has marinated for 20 minutes or so, pan fry it so it turns brown. Do this in batches if you have to. I've read about pouring out the oil used to pan fry the chicken. I'm afraid that it might get rid of a lot of flavor. I don't exactly drink the sauce, so I don't see too much harm in leaving the fat for the sake of flavor - I leave the skin on for the same reason.
After all the browning/searing/frying, add the marinade back into the pan and simmer for about 30 min. This is another point of divergence: my uncle simmers for 25-30 minutes then adds the vinegar in the last 5 minutes or so. I made the mistake of adding the vinegar to the pot at the same time as rest of the soy sauce marinade. The results were awesome. I cooked again trying my uncles way and I found that I just preferred the taste of the vinegar being added much earlier. I think it helped make the breast meat more tender.
1 kilo chicken parts (white meat works fine in the recipe, but it's important to have some dark meat for some chicken fat, the white meat comes out good and tender)
1-2 bulbs garlic - peeled and sliced
3/4 cup soy sauce - dilute to 1 cup with water (I use Pearl River light soy sauce)
2/3 cup rice vinegar (my preference Mizkan + 1-2 Tbsp brown rice vinegar) - dilute to 3/4 cup with water
3 bay leaves
1 Tsp black whole pepper pepper corn
Set vinegar aside, combine chicken parts with soy sauce, bay leaves, garlic and pepper. Wait 20 mins.
Pick chicken out of the marinade and brown in a pan with oil. Don't crowd the pan. Once all the chicken is brown, add the marinade and vinegar back to the pan. Cover and simmer for 30 minutes.