I was never happy the way cotton wool looked on tanks, guns which had been knocked out so I decided to make my own smoke markers & damage markers.
Ok this is not the cheapest option but I think it looks brilliant, first thing you need is some extra models and then you need to buy 6 x explosion markers from Lancer Miniatures
Damage Markers
Late war Sd.Kfz. 251 damage markers
Early war Sd.Kfz. 251 damage markers
Russian trucks damage markers
Russian t34s damage markers
Smoke Markers