how one can create hd like preview images in 590*700 px. please guide me.
thnx
590x700 is not HD. To create a preview image for example, open the software you use, photoshop, illustrator, any, create new document 590x700 and done! Drag and drop to canvas or paint anything you want for your design and save it. Do you mean something like that?
It’s all about what want to create. No need to create same previews with others. Many authors have 590px width and whatever height (700px and up).
For example, here is preview rules of graphicriver:
“590 pixel wide JPG preview of your file. JPG can be any height, however recommended height is 700 pixels.”