Your aim is to take on the train enough for essential comfort and not one item more.
Limit yourself to one dark dress or suit. Many mothers have found an apron a convenience, one that could be slipped over their dresses when they were caring for their babies. Additional clothing for yourself can be checked and sent on ahead.
Clothes, diapers, and such.
—Carry an abundance of changes for the baby or toddler. But plan to dress him simply in clothes that are easy to put on and take off.
Remember weather may change and many trains are air-cooled. So take along a warm outer garment, preferably a sweater, and a blanket for the baby.
Unless your baby has completely mastered the art of keeping dry, use disposable diapers if you can possibly get them. If you cannot get them, then the next best bet is a supply of standard diaper linings—specially treated papers about the size of ordinary cleaning tissues, used with cloth diapers.
Many mothers prefer to use cloth diapers at night. Some babies become badly chafed if only paper diapers are used. Used cloth diapers can be wrapped in wax paper and repacked in your suitcase or put into a waterproof bag.
If your baby is sufficiently trained to use his own toilet seat, by all means take it along. He is less likely to be frightened if there is this one familiar thing in his strange surroundings. Some toilet seats come with a carrying case. If the one you have did not, then use a canvas laundry case or a shopping bag for this purpose.
Pack the baby's clothes, diapers, and blankets into a special suitcase or bag. Keep it unlocked and easily accessible on the train.