What is the best way to pack a suit to reduce creasing?

The following is what I do whenever I am travelling and have to carry 1 or more suits in my luggage.

1. Spread the jacket facing you on a flat surface. From the inside of the jacket reach out for one of the arms and pull it towards you, such that its now inside out.
2. Stuff the inside out arm into the other arm (again from the inside), this has folded your jacket into a vertical half. Ensure that the arms are not crushed in, but neatly tucked into the other arm. Also ensure that the jacket is folded along the centre vertical stitch that runs along the back.
3. Put the jacket aside and fold your trousers neatly and place them on the lower half of your jacket. Fold everything else you can and place over the trousers like undershirts, t-shirts or a bath towel (if you carry them). Ensure that you do not use any clothing item that has a zipper, button, hook etc, as they may leave imprints on the jacket.
4. You can now fold the upper half of the jacket to meet the lower half, such that the other clothing items have formed a padding in-between. This can now be put into your luggage. As far as possible, keep this package at the very top.
5. Once you reach your destination, ensure to unpack immediately.
6. In case you notice some creases, run the shower at the highest temperature you can and hang the jacket (on the curtain rod, maybe). The steam from the hot shower will ensure that the crease disappears. Of course ensure there is not water splashing on your jacket.

Buy it at the destination.

Best size-reduction you can have.
Reduces transportation problem to dollar bills or credit-card size.

Additionally, no more need to worry if the suit still fits or not.
If you can put it on the bill of expenses – perfect.

I had to take a suit backpacking to a wedding in Iran this year. I was introduced to the Skyroll Garment bag, which I was allowed to use as carry on OR checked luggage on several airlines.

The bag unrolls to have my shirt and suit inside, and has pockets on either end for accessories and shoes. Very impressed with it, and there was virtually no creasing after a couple of weeks in the bag!

Do not pack the suit! why spend time ironing/pressing the suit at the hotel/accommodation while you can carry them as they are with you?

Put them in a travel suit bag, something like this:

Once in the plane, ask a cabin crew member to hang it for you, in every plane there is a coat compartment and they will be happy to do that for you. This is what I would do as a frequent business traveler.

Many airlines do not count this among the cabin luggage allowance, so your allowance will not be affected.

My method is a combination of clothing that does not show creases, like skirts that have creases as part of the design of the fabric, or do not crease, with wearing the parts that do not pack away small.
My favorite travel skirt is of thin silk which packs away very small, two of them in the space of one T-shirt, it does not crease on packing and can even be washed and hang out in case it does get dirty underway.

If I need my nice jacket, I will wear it onto the plane, take it off before sitting down and place it on the coat hook on the seat in front of me.
If possible I cover it with my rain jacket, otherwise I will be very careful with drinks and food. I try to get a window seat with a normal row of seats in front of me, so I do not have to put everything in the overhead lockers.

For those items of clothing that need it, the old trick of hanging the items in the bathroom while taking a shower might be enough. Better bring clothing that does not need much.

This method works for me, who does not often need nice clothing while traveling and certainly not for business meetings.

I always pack using the rolling up method:

Starting with underwear and socks, I then roll t-shirts round them until I have a roll that I flatten. Around that I roll work shirts, and then finally any suits I am taking.

This ensures there are no tight folds or creases on anything other than underwear and t-shirts.

Very straightforward, and once you reach the hotel, you simply hang them up.

While many flights have coat compartments, especially for business class, as a very frequent flyer I find them very inconvenient, sometimes having to wait for my suit bag to be delivered back to me, sometimes having it come back creased, and once not come back at all.

It doesn’t directly answer your question, but I usually prefer to wear the suit and pack the other clothing, at least on short flights.

Try Youtube, you have tons of videos that shows how to do it. The “best” is subjective, it depends on your suit type, your packing skills, etc.