Sleepwear
Sleepwear can be pretty diverse. Some people prefer to sleep in the nude while other wear full pajama sets. Either way while camping and not knowing what types of bugs and plants may be in the area it is best to try and stay somewhat covered up.
You will want to keep in mind your head, your body, and your feet. The basic idea is in the warmer months you want breathability while in the colder months you want warmth. It isn't all about your clothes, it is somewhat of a package deal with your tent, sleeping bag, blankets, clothes...
Your feet may not need covering up during the summer months, but keep in mind that they can become quite dry. Sometimes it helps to sleep in socks with some lotion on to keep them moisturized. In the less warm months you may want to consider socks, while the winter you want to look for warm socks, something in the wool category.
Your body again in the summer months you will want to focus on breathability. Something light and loose. As it gets colder you will want to start considering more layers and thicker materials. Fleece and wool become much more attractive as you start to try to stay warmer. If you are camping in the north during the winter you may want to consider sleeping in much of the layers you wore during the day. Merino wool is a huge game changer. It is not fine and soft, but also doesn't hold onto body odor. If you are starting to smell after a few days of camping you won't transfer it to the clothes. On top of that it also moves sweat away from the body so if you get too hot and sweat a bit you won't end up freezing from the cold.
You head is something that is easy to forget. A beanie is a must have if it is chilly or cold outside. This will keep much of your body heat in as we lose much of our heat through our heads. But, even in the warmer months you will want to consider other items with your noggin. You may want a sleep mask to keep out unwanted light or ear plugs for noisy neighbors.