I'm bad at following instructions. Here's several tips. :)

• A washing bag (e.g. Scrubba). The bag and a dry bio-compatible laundry soap weighs the same as one pair of wool socks. Using it means you can cut out underwear/shirts/socks bulk for a slightly higher camp chore load. Very useful for weight/space sensitive camping and doubles as a dry bag!
• Prefer good clothing over sunscreen (big hat, long-sleeved shirts, buff, sun gloves, etc). It's lower weight, less greasy, and doesn't run out. When using sunscreen, stick form tends to be light and easy to pack.
• Camp shoes. Always bring them. Crocks, thin flip-flops, anything but a tight shoe that you spent the last 12 hours in.
• Avoid cotton in general, but also look for quick-dry clothing. Being wet sucks. Being wet for long periods of time can be dangerous.
• Umbrellas are amazing. Shade when there is none and amazing at avoiding wet-out. Very useful for short trips and car camping, though I sometimes bring it backpacking even with the added weight.
• Light (1lb / 0.5 kg) camping chair. If you're young enough you could skip this, but my god is it worth the weight after a long day.
• Wear warm clothing in your sleeping bag/quilt. Bag ratings are inconsistent, often assume you're wearing clothes, and are labeled for "won't kill you" rather than "you'll sleep like a baby."
• A good sleeping pad with a solid R value. It's as important as your top sleeping layer.
• Dry electrolytes, especially in warmer areas, like SaltStick or Gatorlytes. Hypotonic dehydration can sneak up on you and you cannot escape it by drinking more water. This is particularly dangerous with aerobic camping, like backpacking or bikepacking. Hypotonic dehydration can be mitigated with the food you pack, but it's a lot to plan ahead on and complicates re-hydration with caloric intake. Do not avoid high-sodium foods unless your doctor has you on a low-sodium diet (in which you should also discuss with your doctor about your outdoor activities).
• Sleep with your electronics. Cold weather will kill your phone's battery.
• A portable bidet (e.g. CuloClean). There are many places where you must pack out TP (sometimes everything). Less TP means less to carry in and out. It's also very clean feeling.
• Similarly, WAG bags are nice. Zero trace and you don't even need to dig a cat hole.
• Ear plugs. Nature is loud sometimes. People in campgrounds are even louder.
• A small towel or sponge to wash with. It's nice to wipe off sweat and dust, even if it's not as good as a full shower. It's multi-purpose too. Moisture on your single-walled tent? A quick wipe and no indoor rain for you.