"Cropping" after image rotation

I've just purchased your programme and having a slight problem. I've rotated images to the correct orientation and am now trying to "fine tune" the cropping as they are old photos with white borders. The cropping (by dragging the borders on the "thumbnails" on the left) does not seem to work that well. Should I crop them before rotating?
Thanks

Hello William. Thanks for your feedback. Dragging works the same regardless how much the photo has been rotated. What problems are you facing after rotation?

Thanks for prompt response!

It does not seem to be very accurate (I'm watching the zoomed in image). I'll try again!