If I'm designing the look of a website or mobile app, what is the best method of going about it before sending it off to the programmers? I am proficient in Photoshop so I've started building it in layers, but I heard something about making each layer into a button? I'm still not quite clear. Cheers.
First off - designing a complete front-end in PS is bullshit. Second, you should talk to the developer while designing, and the employer, to see what is needed. Most things one used to use images for can now be accomplished using CSS - which means the major part of creating the website will be a mock-up/wire-frame, so the coder can see what is needed where.