Depends if you want to serve it as a side dish or the traditional north african way.
As a side dish served cold, make a vinaigrette with lemon juice, olive oil, fresh parsley, crushed garlic or chopped green onions, black pepper. Add to the cooked couscous, you can add diced red pepper or green. It makes a pretty good salad, but be careful it packs quite a few calories.
The north african way is a little more elaborate and hot.
sauté some skinless chicken until golden, add one onion, garlic c love, chick peas, zucchini, turnip, carrots, potatoes, bay leaves, salt, pepper, cumin, tomate paste and cover with water and cook until the vegetable are tender. Cook the couscous as suggested on the box and serve it.