first of all do the keyword research with the google keyword tool related to your business websites for which you asking keywords.then after creating keyword research see the same theme websites trends and searches,then decide the targeted keywords
I don't think excellent keyword analysis tool other than adwords keywords tool. Some other similar keywords tool webceo, semrush etc.
I use 3 different keyword tools, market samurai, keyword sniper pro and trend miner pro, all are very valuable resources, to dig up the gold
Another the adword keyword tool there is keyword discovery, work tracker, etc are the tools where you can find keywords related to your theme, and you can also find more phrases of keywords.
I have used wordtracker combined with adwords keyword and they work pretty well to find new ideas for keywords when you use them together.