Foreshadow sparingly, too much gives the twist away.

Definitely work backwards with the twist in mind. If you foreshadow, use small tells, not large explosions. It will depend on your genre. Generally twists come down to deceit on one level or another. It can be deceit on either side. So your protagonists can trick the antagonists as much as the other way around. It could be a twist neither knows but a third character does. If you're writing in a genre that relies on twists, played right, not having a twist could be equally as effective.

Think about an obvious way the plot could go and then do the opposite. Like, there is no surprise party, his friends really are ignoring him.