Hi mate,
If this is your first dio,you are def. on the right track(

).Two comments i do have though is that the area to the left of the dio looks a little too much like a set of steps,maybe if it was sloped out a little it would look more natural.You could also maybe add more snow to white out the front area before the tank as kind of gives the impression that another tank has been through there in exactly the same movement.
I like the whole winter feel for the dio and the weathered look of the tank and with the side hatch open you could incorporate a figure of some kind to give the scene some more life.
Best of luck with the rest of the dio and have a Merry Xmas,
Cheers,Shay