Marcus need to do a few things in order to have a breakout year:
1. Ball Handling: Smart needs to get much much better at his ball handling in order to create space, penetrate, blow by his defender, and take it to the rim. Ball handling will allow him to become a real triple threat.
2. Become more Explosive(first step and taking it to the rim): He has the highest body fat % of any point guard, and he had a very hard time getting by his defender and penetrating. In college he could dip his shoulder and get by most everyone, and he thought he could do that in the NBA right before he was drafted. Anyway, if Smart works on his explosiveness and gains in agility and speed; think about how much more explosive he would be if he lost enough bf% to be around 5-6%.
IMO Smart is the strongest point guard in the NBA. The draft express databank shows his measurements and times; I have not found a pg that comes close(please tell me if you think there is a stronger pg). Losing weight will not make him weak or hurt his hame negatively, IMO. The easiest and best way for Smart to get that explosiveness is a 1-2 punch of agility and speed gains, and trimming out and losing his bf%.
3. Thats it. The two pillars of Smarts breakout year are BALL HANDLING AND EXPLOSIVENESS. I think the other stuff, like improving his shot, will come naturally if he makes gains in the 2 areas.