[FFmpeg-user] best FFMPEG encoding and encoding a file to fast start

[Dani A]

Two questions, what is the best enconding to be used to convert a video file to lower size file while maintaining quality?
Also, I want my video to start streaming right away so I have been told that I should move the moov atom to the beginning for fast start. 
So can you give me the full ffmpeg command to do that including the best encoding?