Preparing a PSD?

Are you preparing a PSD in preparation for development? This check-list will help you avoid common errors and save time/money during development.

Document size. Does the width of your design make sense on the web?
Fonts. If you’re using any non web-safe fonts, do you have a web version (Fontdeck, TypeKit, Fontspring, Google Web Fonts, etc).
Colours. Though many print designers use richer colour spaces, the web uses sRGB, so make sure your design looks satisfactory in the sRGB colour space.

Named Layers. Make sure all of your layers have a descriptive name.
Layer Groups. Make sure all layers are organized into groups.
Layer Masks. Apply all of your layer masks before sending the psd.
Blending Modes. Keep in mind that blending modes can’t be used on the web as they require knowledge on the layers around them. ‘Multiply’ is a particularly common blending mode that I find in psd’s. Anything using a blending mode will have to be exported as a flat graphic.

Hover/focus/active states. Indicate all desired hover/focus states in your psd. A good way to do this is to duplicated it the layer group and name it something like “Primary Nav: Hover”.
Responsive. If you’d like your website to be responsive, please provide layouts for the various target sizes (tablet, smartphone, etc)