So here's the deal:

I've written several songs now (instrumental prog/post rockish) but I'm unhappy with the composition and the lack of emotion coming from them. To me, they sound like empty riffs/melodies, etc. combined into a song.

So, I've been working with a new verse/chorus idea I have in addition to an ending. I have a feeling for what the song should sound like in my head but I've been messing with these ideas for a couple months and can't get anything I like (I could make a song but not the song I intend).

Currently, my method for writing songs is to sit down and jam, working with what I have thus far for the song until the right things show up. What am I doing wrong? Would learning more about composition help this? Another thing that doesn't help is that I only get less than an hour to play each day.

I'd appreciate any advice on improving my writing. Thanks!
This may not be the answer you are looking for, but quite a lot of instrumental songs lack emotion. Learning theory always helps, but as for the emotion in the song, it can all come down to something as simple as the phrasing of passages.

Another tip is if a melody sounds empty, adding a harmony to it can add life.
I see what you are saying but there are still plenty of instrumental bands out there that have very emotional music. I do realize vocals add a lot - I'm just wondering if there's something I'm missing about songwriting/composition.
You have to work on getting THE song in your head. Concentrate on what you want it to sound like; the phrasing should be just as important as the notes themselves. Then try and translate it to the guitar/drums/bass etc. It's great that you kinda have a song in your head, and that's a great starting point. Not many people have that ability developed as far. You just have to work on aural (ear) training. Sooner or later, you will get better at this and the song(s) will be more apparent in your mind. You are kind of on your own with this one, but ask me any questions if you like. Hope this helped :
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