using the plastic from the cleaners helps *

This is correct

And get a bag that can handle suits without creases.

Go to the 1:00 mark for the inside section:

Anything that has a system that folds horizontally, when coupled with the plastic from the cleaners and you should be set.

Yep. Suits and shirts go horizontal. Everything else folded *

This is what I do

The investment in the suitcase has been well worth it, I travel confidently that my suit will arrive ready to wear. I used to bring it in a suit bag and ask a flight attendant to hang it up for me, but found that airlines became less and less accommodating of that request.

They are ridiculous about it now

Even if you have status and are sitting in first class, they still look at you funny if you ask to hang a small garment bag.

This is exactly what I've been doing for 20 years without

any significant wrinkles. Hanging it overnight usually takes care of anything residual. Same thing for dress shirts.

That's my trick

I use a plastic cover from the dry cleaners and put my suit under that. Then I place that plastic inside of a plastic or cloth suit garment bag that zips up. I fold the garment bag over once, sometimes twice (depending on size of luggage I'm packing it in) until it fits inside of my bag. I've never had a problem with wrinkling and I think the plastic slip is what's key because it creates a barrier and clings, eliminating the friction from rubbing against other materials or other parts of the suit.

I do the same aproach as Brandon *