If you need to pack your neoprene wetsuit or drysuit then the first rule is to never fold it. Every time you fold neoprene you create a crease by squeezing the tiny bubbles which not only looks bad but will greatly reduce the warmth in that area of the suit.
Consider hard parts of the suit such as zipper pulls because over time and with any weight pushing down on them these can bed into neoprene, crushing that area. Gently warming a wetsuit and moving around wearing it can help to remove creases but it's best to avoid them forming in the first place.
If you're storing your wetsuit or drysuit it is best to hang it on a large coat hanger so you never have to fold it and you reduce the chance of creasing. A wide hanger spreads the weight of the suit so the hanger doesn't dig into your suit.
If you do have to fold your suit then try to keep the folds as open as possible with padding so the suit doesn't pinch at the fold. In the industry, we use strips of foam or cardboard tubes that round the folds but if you don't have any of these then you can use bubble wrap, old plastic bags, newspaper or similar to create rounded padding that you can stuff where you're folding.
Start with the suit laid flat on a surface and consider the areas that are ergonomically designed to bend such as knees, shoulders and the waist. With the front of the suit facing the floor bend the knees with some padding behind the knees and then repeat around the waist so the legs are both folded up into the back of the torso. The arms should naturally wrap around the legs now and that is as much as you should really fold a wetsuit.
If you need to pack your suit to ship it somewhere then you need to protect it as much as possible so put it in a box. A box will protect the suit from crushing or folding further.
1. Lay your suit flat on a table with the zipper done up and the zipper is against the table.
2. Lay some packaging, like scrunched up paper or bubble wrap over the chest and roll the suit over it from the neck avoiding any folds. Keep rolling until the suit forms a cylindrical shape.
3. Put your wrapped up suit in a big enough box that it won't be crushed or folded.
4. Lay a section of cardboard over the top and bottom of the suit to protect it from box openers.
Images provided by Fourth Element.
Creases in neoprene do reduce the insulation of that area but they are not always permanent. Almost every suit will have a crease on it somewhere and it is not a reason to reject a wetsuit, because you can get rid of some creases yourself and it will be hard to find a wetsuit without at least one crease, even from new.
Obviously, DO NOT IRON your wetsuit or you will literally melt it but a bit of gentle warming and moving the area can sometimes reduce the creasing. But the best way to get rid of a crease is to never crease neoprene in the first place. It is very hard if not impossible to return a suit to it's former glory.