everything looks poo in game

I make some fairly nice stuff in photoshop, but say i put it in a game like rtcw, it just looks crap, the main problem is theres never any depth to my images, ive been trying to make textures now for years on and off and i just cant seem to get the depth, anyone got ideas? im making grass, metals, bricks etc, not using any photos, but what looks good for say a website looks horid in most games today

shadows and highlights. that's what it's all about. once you master that, you can make them have depth. i don't think a tutorial is going to teach you that though.

great