I've been playing around with adwords editor and am getting good results with it. With a 3k+ keyword list, it'll let it do its initial group of grouping. After that I'll manual edit the groups. For instance if "payday loans" has 400 keywords, then I'll go back to the generate common words screen.
payday loans has 400 words and I'll eyeball the keywords in the groups and see if I can notice any patterns.
advanced payday loans - 30 words
fast payday loans -25
payday loans instantly -30 words
but I just keep doing this back and forth, eventually I'll break the 3k list into many tight, 30 word keyword groups.