Being smart means being able to solve a specific, difficult problem. Being wise means always having enough options that you never have to take on an especially thorny problem in the first place.
Resisting the time pressure others put on you is an important step toward keeping your options open and becoming wiser.
There are many negotiation techniques, but over the long term your greatest bargaining advantage is a growing set of alternatives. Eventually the very idea of having to “negotiate,” along with all the other party's demands, looks absurd, and you can walk away without hesitation. The basic mistake young people make is assuming they have few options, then rushing to make concessions and grasping at any straw they can find.