Piece for orchestra

I just started this piece for orchestra. I really like it so far, but I don't know what to add for melody after what I have, any suggestions?

(After the music stops that all I have.)

It's sounding very cool.

I'd remove the double bass and cello lines in the first two measures, just to make it a bit lighter in the start. Of course, it's just my opinion.

Besides that, it's a nice start. 

It seems to me you have two basic options:

1) Create a quick-paced melody that's very bouncy and dance-like. 

2) Create a bigger, more grand melody that stretches over entire measures and rests on top of the quicker 6/8 texture.

Either way, it's up to you; perhaps you'll find something completely different to do. It all depends on what the piece is for and what your general idea is for it.

Good luck on the rest of it!

I like the subtle beginning. You did a good job of translating it to the louder melody. Unexpected but nice. I would follow Celloman99's and Jean Szulc's advice.