Teriyaki sauce substitutes I can use today?

I'd like to make teriyaki salmon today. I don't have any bottled sauce so I'm going have to make the sauce from scratch, but I won't go to the supermarket today just to buy extra ingredients. Can I still make a tasty sauce without stuff like mirin or sake? I don't have any plum wine or anything alcoholic. The ingredients I do have are dark soy sauce, light soy sauce, sugar, salt and garlic. What can I make out of that? I'll need a marinade for the salmon and some sauce to pour on top of it when the fish is cooked. Thanks for any tips.