Wrap vertical wooden column with drywall

I want to wrap this vertical wooden beam with drywall so that it blends in with drywall near chilling area as you can see in picture.

I have done some drywall repairs in wall but haven't done something like this. I know that I just have to screw drywall pieces on all 4 sides and use joint compound followed by some sanding. But not sure how can I achieve straight 4 corner edges. any tips or links to online articles will be appreciated.