I for one think...
e.g. you are doing it wrong......
What exactly does it mean?
- Peronally I think...
- I think in the first place that...
- merely: I think that.....
If you say "I for one think XYZ", it implies that you are not expressing your view in a tentative way.
Perhaps the underlying meaning is "At least one person, i.e. the speaker, thinks XYZ; and there may well be others who agree".
Not a professional ESL teacher.