I create a .psd first; to cut it up I use different methods depending on how complex it is.
Slicing works, but it's over complicated most of the time. It doesn't decide what should be a repeating image, so it still doesn't get you completely there. Plus tables suck
Sitegrider is decent, but not my cup of tea.
I generally use ctrl-shift-c to copy merged and get my images that way.