There are few tools or methods to tweak the resoults you get with these tools, but those are for advanced users.
If you are an advanced user I don't think I need to mention them, because you already know them.
A few trick though for everyone, free trick, comes from google:
1. Related Seaches
2. Wonder Weel
Step One 1.
Other than this, you dont need anything else to do your keyword research :)