Try to find one that doesn't have the ball socket/joint. It looks sort of like a handle. This will make it much easier to score. It may not always be possible but it really helps.

The size of the shoulder may vary. I prefer on closer to 7 pounds but one that size isn't always available. The last one I used was 9 lbs. The main difference will be the cooking time. The bigger the roast the longer to cook it.

Also sometimes there is a little extra fat that is not needed so I cut that off.

I mentioned two ways to cook a pork shoulder. Here you have the oven version. The crock pot version is just as simple, just cut off all the skin. If left on it will be super chewy and not at all appetizing. Next use the same rub but just add it to the pot, you may want to increase the amount and add a bay leaf. Also still you can still poke holes into the meat and put garlic in them. Or rough chop the garlic and add it like the spices. Also you will need water to keep it from drying out. Adding a little orange citrus is nice, but not necessary.

* You should treat this like you would a regular roast*

Cooking time and temp varies with each oven. Keep an eye on your roast and baste the shoulder with juices. I like to check and baste every 30minutes or so. You don't want a dry shoulder. Dressing for slaw - taste and add more fish sauce or vinegar for your preference. Prep time does not include marinading time. If it's already too hot for you to have the oven on for 5-6 hours then use a crock pot for the roast. Just cut the fat off and pierce the meat then put the garlic cloves in the holes before you marinade. Also since you've cut off the fat, keep a good eye on it so it doesn't get dry. Cook on low for about 4-6 hours. You will know when it's done, it should fall off the bone.