I have a hair thing. It’s complicated, so I need to carry a full-size flat iron and a 3.5 ounce size container of hair serum. These are my no-compromise items. I even purchased a lightweight flat iron, with a built in cover, that I keep in my travel bag. Some people have skin issues and require certain products to keep their skin clear. For me, it’s all about the hair.
Know what your item or items are and bring them if they are absolutely necessary to make you look and feel good. Consider what you will have available to you at your destination and if a substitute will suffice. If your items are beauty-related, consider a visit to your local beauty store or department store for samples. I have tiny sample tubs of foundation and moisturizer that I keep and replenish so I always have my favorite products with me. I keep a pre-packed toiletry bag since I travel a couple times a month.