some tips:
You basically want to look for 4 things in a keyword:
a) traffic
b) competition
c) cpc (i.e. not just the obvious - how much it costs - but how much market value a keyword has; GENERALLY speaking, anything over $2+ is "in the money"...i.e. if someone is paying that much for it, unless they are stupid, i.e. some big company that doesn't care, they have to be profiting pretty well to justify the expense)
d) COMMERCIAL INTENT. This is one HUGE one that even seasoned IMers don't really focus on as well as they should. One way to judge intent is to go for action words....
Let's say you are selling "blue widgets" you want
"BUY blue widgets"
"FIND blue widgets"
"blue widgets OFFERED"
one thing you can get to use is the negative search - see what word stems people in your niche are using. By that just take out the root word and what is left is the word stem.....are they using action words/verbs? colors? location? price...how are the words being used in your niche
Finally, become friends with Adlabs commercial intent tool. Sometimes the difference between the singular or the plural can mean alot in terms of commercial intent. Some colors as word stems may have more commercial intent than others...some locations...etc, etc - get what I mean?
Of course you can also use tools like semrush and keywordspy to see what people are bidding on. But you can't just grab the words, throw 'em in a campaign and profit. Use them for research - think hard.
Detecting Online Commercial Intention: Audience Intelligence: adCenter Labs
I'll leave the rest up to you.
Good luck bro (lol'ing for ever on this one...)
ps
tired and didn't review for spelling but you get the drift....