* Please don't move this to Music Theory - it's not a theory question.
I've spent a lot of time learning how to play modes. I have all the modes completely memorized in the most common keys. I know what modes are, how they are made, the "theory" behind them, etc. So, the question that remains is what good are they? How do people use them to create songs? Do people sit down and say to themselves, "I think I'll write a song in G Lydian today....."?? Or is it more like - you sit down and come up with a catchy progression using the chords of D Major but you decide it would sound better to focus on G and get a "Mysterious" melody going so you use G Lydian? Am I thinking too much or what?
you could find some songs written in the various modes to see how other composers have used them. or you could just try to come up with something using a mode... fiddling around until you come up with something you think is cool. or you could just not worry about it and play whatever you feel like playing, and if it is in this mode or that mode, you will then be aware of it.