Use a modern codec like H.265/HEVC or AV1
Keep the original resolution if possible
Match the source frame rate
Use a variable bitrate instead of a low constant bitrate
Set a high-quality encoding preset
Use two-pass encoding for better efficiency
Avoid unnecessary re-encoding
Remove unwanted audio tracks, subtitles, and metadata
Crop black bars before compressing
Reduce noise before encoding if the source is noisy
Use a smaller bitrate only if the content allows it
Choose a container like MP4 or MKV
Compress from the original source file, not a previously compressed copy
Test different settings on a short clip before compressing the full video