Start by imitating people whose style you like. Then you can use what you learn when you're making your own music.
I listened to the video you posted and here is what I hear:
- Basic 2-beat pattern for 7 measures (if in 2/4)
- Simple fill (one note at a time, 3 or 4 notes in a row) for 1 measure
- Repeat with a different basic pattern
I heard the following basic patterns used:
Low string eighth note, middle string eighth note, high 2-note chord quarter note
Large chord quarter note, middle string quarter note
Large chord 2 quarter notes in a row
If you want to get obsessive you can always go through the recording and try to imitate it in an exact note-for-note way, or look for a printed tablature, but if you're just looking for fresh ideas you might just try this kind of careful listening to a lot of different songs in styles that you like.