Usually how do you guys checkout and ask seller to send to forwarder? Want to explore thjs option. Do you key in the address of the forwarder?

I do always buy from taobao but just use their own shipping, mostly use ship (quite cheap) and sometimes can get cheap air mail too.

So this means i will need to engage the forwarder first.
When engaging them do i need to specify how many items and weight going there first or engage them then item reach there only the quote me shipping price?
Sorry for noob question cause never use forwarder before