My band recently decided that we should write songs and do our own thing. I was curious whether it would be more influential to practice as a band writing the song together or work on writing the melodies and riffs away from practice. I just wanted some input on which way would be the most constructive for a practice session. Thanks for the support. !
Do both, Set aside some of your practice session for a jam/improv and if anything good comes up, remember it, and use it. But also work on riffs/melodies in your own time at home. Lyrics you can do by yourself, just putting it to music with be the harder part.
Make riffs and stuff on your own, then play them at practice, they will lead onto jamming and improvisation which in turn, becomes a song.
Do both, coming up with lyrics, riffs etc. at home is great, but if your serious about writing make time at practice to work on writing songs.
just try and remember the cool stuff, that was my problem i'd forget everything. :P
No major projects so far, will update that as soon as something real starts to take place. :P
whenever i jam with my friends i leave a recording device going so that if we come up with anything good i remember it.

band practice/jamming is good for really getting idea's flowing.
however i find it easier to refine the idea's when im by myself.

good luck
What my band does is we all write songs (just lyrics) and then pass 'em around. We give our input, advice, ideas, and just work out a beat and see how we can get it to sound.
Have a good one,