Character modeling/best practices/ workflow professional?

I would like some input for someone who has worked in the gaming or animation industry.
I have been studying Character modeling and have a question. If I am modeling a character with clothes.
Do I need any polys that would not be seen?
If i am modeling character wearing a shirt does the head and neck need to be connected, or does the neck just need to be extruded down into the shirt.
Is it ok have the arm and hand just inside the sleeve, not connected to the shirt.

The above Questions are the general direction I am wondering about.
I want to start modeling with animation in mind. ( rigging and so on )

for game models, all unseen polygons should be culled. if you aren’t going to see it, it’s just wasting space.

It all depends on how your character is going to interact with the game world and how far it is from the view port.
Consider this. If the clothes on your character are animated ( like waving cape, removable shirt jacket, shoes etc) then create the full model of your character and create clothes over them . If the dress is not going to change. then you can connect your head and neck with the shirt and pant. but you do need some more polygons near the joints so that your model can deform easily.

A shirt is a shirt. A body, a body. good practise for both animation and illustation to me;)

Thanks for your replies, all of them help.

I’m currently working on a character in a suit and tie with a white dress shirt. I didn’t model his body underneath since you won’t ever see his bare skin other than his hands and head. I did model the entire dress shirt underneath, but I used the mask modifier on parts that are covered by the suit coat.

Since this isn’t for a game, I can’t help you there, but for other characters that I’ve done I’ve modeled everything and hidden the parts that might poke through. The hard part is getting everything weight painted correctly, but the copy weights tool takes care of most problems.

Thanks for all the great replies, it really helps.