I'm not the best person to ask, I've only been playing Commando a couple of weeks, but here's my thoughts.
1) Be patient. Commando doesn't do a whole lot of damage and he doesn't have loopable pressure. When Kung Lao can confirm into 40% easily, the temptation is to hastily get in and return the favour. That leads to ruin. The times I do best with Commando are when I'm patient and level headed.
2) Learn to enjoy blocking. Kano has a good reversal in terms of EX up ball, and parry when used well, but they don't lead to big damage. Learn to block well, which strings/combos can be interupted by parry, which moves are +/- and by how much, so that you can play smart and maximise your opportunities.
3) Watch UltraDavid's option select videos and learn how to OS off of d1 and d4 so they come out on block only.
4) Get 'em in the corner. Kano's corner combos max out at around 40%, which overall isn't great. However, the effect that being kept in the corner has on an opponents mental state is. Fear of lengthy combos and starting a round in the corner causes reckless behaviour, which your tool set is built to capitalise on. If done right, each of Kano's pokes and parrys can lead to 20-ish %. Again, not great, but when it comes to chipping away at your opponents confidence (getting a successful parry is the ultimate way of saying 'I'm in your head, asshole') it's excellent.
Ultimately, Commando isn't a grappler, he's a footsie character with the bonus of low damage projectiles, command grabs and parries. Success is built on patience, solid reads and chipping away at your opponents confidence. There is something about being hit with a 16% command grab that really upsets people. When you finally get a win, it's so much more satisfying.
But like I said, I've only been playing him two weeks, so what do I know?