You've just received your digital embroidery proof. It seems okay but its hard to visualize how it will look embroidered on a shirt. How can you tell if it will look good?
Background - Is the background color the same color as the shirts you ordered? If not, your logo might look completely different so you should request to see a proof against the "shirt" background.
Size - You should know the actual measurements of the design rather than judging it by how it looks on your computer screen. How can you check the size if you can't print the proof at the correct size? Cut a piece of paper to the right dimensions, tape it to a shirt in the proper location, stand three feet away and visualize your logo.
Fabric Type - A logo can look very different depending on the type of fabric its embroidered on. Elements such as small text can be clearly readable on some fabrics while unreadable on others. If you're uncertain how your design will look its best to request an embroidered sample shirt so you can see exactly how your design will appear.