We all know that it's not easy to get a US visa if you're a Filipino but it's not impossible. Many Filipinos chose not to apply due to fear of rejection despite their strong cases. There are many many subtle signs that visa officers look for but two big ones are:

Your hair -especially for female applicants

Your ability to speak English

Right or wrong hair is a sign of social status and in non-immigrant visas the visa officer is trying to ascertain the applicant's social status more than anything since that's the number one indicator of whether or not the applicant intends to return once their visa term ends. I recommend you go to the salon a day before your interview.

As far as English is concerned I think you already know that but it's especially strict in the Philippines compared to other countries like Vietnam or India. A visa officer stationed in Manila will expect you to have near-perfect English and for goodness sake PLEASE don't say 'ano' as a filler word during your interview.