Depending on the size of your calamari you'll want to slice the tube to flatten it and score the inside in a small checker pattern so the tube won't curl up. If it's large you can slice it into smaller portions or slice it when you're finished. It's up to you. Again, depending on the size of the squid you can grill the tentacles whole or cut them into smaller pieces.
For 1 1/2 pounds calamari
Make a marinade of:
a couple tablespoons of olive oil
a red chili pepper
a lemon (juice and zest)
a couple crushed garlic cloves
You can add oregano but it can overpower if you use too much
Marinate the squid for 10 minutes while you heat your grill.
Grill on high for 2-3 minutes being careful not to scorch the squid.
Squeeze a little fresh lemon over it and hit it with sea salt and freshly cracked black pepper to taste.
It's great with a green salad, some tzatziki, and grilled veggies. The sky's the limit!
If you want to go for an Asian influence marinate 2lbs of calamari with:
6 T lite soya sauce
1 T sesame oil
1 T sugar
1 t vegetable oil
2 cloves crushed garlic
1 green onion roughly chopped
Marinate for 10-15 minutes and grill on high heat for 2-3 minutes making sure not to scorch the calamari. You can finish with toasted sesame seeds and minced green onion.