By default, dslrBooth sets your template for optimal printing on 4x6 paper at 300dpi. If you have a high resolution printer than can print 600x600dpi, go to you printer settings and change the print resolution to 600x600.
Here's how to do this on DNP printers. Your printer settings might be slightly different.
Then go to Template in the main menu and change resolution to 600dpi.
If you are worried about the Horizontal and Vertical Resolution being low, those numbers are not useful and are not an indicator of the quality of the generated images. File size as well is not an indicator of the quality of the generated images. Please see this article on how DPI doesn't matter for more information.
To get more accurate color rendering on your prints, please see our article on Setting Printer ICC Color Profile for your Printer.
If you have another print quality issue, send us your original photos, your template, your print files, your printer model, and a scan of your print and we will review.