How best to optimise an image in Photoshop?


New Member
Is there a defintive and proven method for optimising images other than the save for web function in photoshop? My main concern is that I have often tried to use large graphic backgrounds in wrapper divs of a web site, only to find that they are outrageously large... however having opted to download a background from a free resource I have found that they are substaniously smaller.. I am creating files typically 72dpi avg 1400px wide to 1500px height. A similar file from a free resource often more glamorous in design as mentioned can be substantiously smaller than mine!