i can also add a few:
1. buy bitcoin not as a short term plan but as an untouched investment
2. if you have cold keys, store it in a secure place where you can easily find it
3. have an emergency money so you don't have to touch your untouched investment
4. always leave options so you can be flexible most of the time.
This is an important point and is the most important of all the recommendations the OP made. It is very important for a bitcoin user to learn how to keep his money in a private wallet and to avoid storing it on trading platforms. The best thing to do is get a hardware wallet. One of the biggest mistakes that many users make is lack of sufficient knowledge of some important details in the Bitcoin protocol that explain the correct ways to use it. There are many threads on the forum that explain these details in simple words.