Something I am missing in LazPaint is fixed proportions for the selection (for example XNView has such).
For example if I need to have photos on photopaper, I could set fixed proportion with the proportions of the paper and then crop the image.
XNView has a set of proportion to select from the popup menu (4:3; 12:9; 5:4... etc.) and also a cutom proportion can be selected.