What worked for me:
1.) Talk to yourself in English for instance kapag nag-mmuni-muni kayo or planning something, kahit mahinang boses lang, and make sure you correct your mistakes (e.g. wrong grammar or pronunciation) by repeating what you said.
2.) Talk to a Native Speaker, if you work for an American/Aussie company for example, take advantage of the opportunity to have a conversation with your English-speaking colleagues.
3.) Watch a lot of English movies and try to study the dialogues and use it kapag may proper opportunity… also it will improve your use of collocations which makes your manner of speaking natural or “native”... Huwag lang naman masyadong OA, baka mamaya nagtanong kayo presyo ng galunggong sa palengke, mapasabi kayo ng “This is absurd!” o kaya ng “That’s rubbish!” magulat yung tindera 😛
Also remember that “Speaking” whether Filipino, English or kahit anong language dapat fluid and natural… hindi yung parang aral na aral that you have to pause for a moment to compose whatever it is that you want to say…