Hey there, Super10ZX! What a coincidence that you got in contact with me! I saw your request a while ago and actually wanted to help you out, but I became tied up with personal matters, hence my late reply. Sorry about that!
Anywho, I tend to use my Windows' built-in Paint application to crop all of my images, which I usually access by right-clicking the picture in question and clicking "Edit". I usually tend to overcrop--cropping at a large ratio and not getting the right dimensions at first, but then using the "resize" option and changing the pixel count while maintaining the aspect ratio and going from there.
I hope that makes some sort of sense, I'm not really the best at explaining intricate stuff like this--I'm better at showing, if I'm honest.
If you need any assistance and help, don't hesitate to ask!