You can create a large number of keyword phrases by re-combining the words in existing phrases. Use the "Recombine" button in the "Multiply keywords" group in KW Manager.
For example, if you have a keyword phrase like
wedding reception decoration ideas
The re-combine option will create
wedding reception decoration ideas wedding reception ideas decoration wedding decoration reception ideas wedding decoration ideas reception wedding ideas reception decoration wedding ideas decoration reception reception wedding decoration ideas reception wedding ideas decoration reception decoration wedding ideas reception decoration ideas wedding
and so on...
Now delete the phrases that make absolutely no sense but keep the good ones.