I think Trump should just continue Obama's foreign policy. Things are going so well in Afghanistan, no need to change anything. I think continuing to ignore North Korea is probably best as well. I think you should tell Bashar al-Assad not to use chemical weapons on his own people, or else! Seems like the Iranian deal is also going swimmingly, no need to worry about North Korea helping accelerate their nuclear program. And if China wants to build  islands in the South Sea and put military bases on them, I think he should ignore that too. You never know, he could get the Nobel Peace Prize. Just leave everything for the next guy, it is your legacy that matters.