Everyone seems to go through this because there barely any examples from Google, I don't know why they haven't improved their FAQ yet. There are serveral threads here on this which I highly suggest you search for and read all...
I'll get you started with this simple tip: every negative keyword goes on its own line by itself and can only affect the entire ad
widgets -blue -red
here was my learning curve, make sure you ignore the incorrect eariler examples in the messages and only follow the more enlightend ones at the bottom of the thread: [webmasterworld.com...]
I have already found out (at a little expense I might add) that
does NOT WORK. Don't even try to do it.
I was trying to exclude the word widgets when it was used by itself for a search since [widgets] means show the ad for just the word widgets by itself.
You'd think they would allow expressions like that but they don't. And worse, it won't warn you of an invalid entry, it just thinks you are trying to exclude the phrase brackets and all (brackets which you can't use on google)