I just have the free version right now so I don't know all that the pro one can do. But even the free version has A LOT of tools you can use, I haven't even figured them all out yet. But one that I have used is their Content Optimizer. You can take a new or existing content piece of yours, and compare it to one of your competitor's pieces on a similar topic, and see where you might be lacking based on the keywords that are used in each piece.
Repeat this exercise for as many topic buckets as you have. And remember, if you're having trouble coming up with relevant search terms, you can always head on over to your employees on the front lines -- like Sales or Services -- and ask them what types of terms their prospects and customers use, or common questions they have. Those are often great starting points for keyword research.
Settings. This tiny gear icon on the right upper corner is where you can ask support for “Help”, toggle on or off the help icons; manage “User Accounts” (you need to enter your Google AdWords credentials when the software is run for the first time plus your Moz API details too, which are free to get since LTP uses a both AdWords and Moz’s data); set the “Data Fetching Speed”; and check the “Show Runtime Error” and “Show Debug Panel” in the “Debug” section (which can be very helpful when there’s something wrong with the tool or with your Google AdWords account).
Depending on your topic / vertical and your geographic location the search engines may have vastly different search volumes. The tool can only possibly offer approximations. Exact search volumes are hard to find due to vanity searches, click bots, rank checkers, and other forms of automated traffic. Exceptionally valuable search terms may show far greater volume than they actually have due to various competitive commercial forces inflating search volumes due to automated search traffic.
It would be great if you can provide comparative analysis of this tool with Google Keyword Planner. Since you’re using this tool so you can provide best comparison. One differentiation which I understood is that this tool works for yahoo and bing as well whereas Google keyword planner works only for Google but Google being a dominating search engine, gives the highest returns, so only this reason may not be enough to buy it.