I had avoided to put in some kind of smoke in the grenade explosion because the smoke "overwrote" the other effects. Then my friend just told me to move the smoke a bit behind the stuff and I felt pretty dumb for not even thinking of that. Doh! So I added a bit of smoke and also tweaked the curves for other effects to make it more dynamic and less static and boring.
The blog of Aydin Afzoud, Senior Game Designer at MachineGames.