I usually come at song writing from a few different places. The start for me now a days is far more lyrical and with what I want to talk about within the song. I used to just write a ton of licks and than put some goofy words to it and there you have it; pure mastery! Not so much.

My approach currently is having something I want to write about. Once I establish that I have a place to come from lyrically, I than sift through years of recorded riffs, progressions, etc. to see what I can find to express this. Sometimes it happens very naturally, other times it does not. From there my greatest writing tool is LOGIC and recording the ideas as they come. Where as the trusted acoustic and pen'n'paper works great, being able to track as you go and never lose an idea is unbelievably helpful and inspiring. From there, I tackle it until it's complete. One thing I strongly recommend is to be concise with your ideas and don't let the inspiration pass you by. I have found many of my best ideas simply come from sitting down, and saying "I am not stopping until this is done." Too many songs can lay dormant due to lack of follow through. Tackle inspiration the minute it comes and exhaust it.

Also, there are moments when I have something particular I want to emulate. I have a song called "That Familiar Place" that was purposefully written to sound like a mixture of Iron and Wine and Portishead. I feel that was accomplished, and my commitment to that I feel developed into a great song that I am very, very proud of. What I find in this vein is that you almost always end up sounding like "you." You can try to emulate all you want, but it will come out sounding like yourself, which is not a bad thing. The influence from your intention will mix with your own personal style and usually a great result will happen. Just don't try too hard to be someone else, as you will come across generic. Borrow from your influences while also intertwining your own voice.

That is the best I got for the time being. Good luck!