I've heard the tips for keeping your clothes unwrinkled in general - rolling t-shirts, having those cell things for shirts in your bag, etc.
However, while those work pretty well for t-shirts and casual clothes, every so often I've had to travel with smart trousers, business shirts, or (recently) a suit!
I didn't risk it, and carried the suit separately, having had that go badly in previous times. However, I can't find an easy way to travel with a backpack and not have creases in my business shirts. IF the destination has an iron, that's all good. However they sometimes don't, and in deed last time for the first time, I burnt my shirt in the process (it was not a good start).
Any solid techniques for keeping clothes uncreased in a backpack?