"What DPI setting should I use to scan a picture for creating a design?"
The correct DPI (dots per inch) setting will depend on the size of the picture to be scanned. The desired picture size is approximately 1500 X 1500 pixels. To achieve this take the size of your artwork in inches, such as 8" x 7", and divide the longest side into 1500. In the example, 1500 divided by 8 = 187.5. The DPI setting of the scanner should then be 188 DPI, and this will produce a picture that is about 1500 x 1310 pixels.