You can record each of your transactions simply in a notebook. The main thing to write why you bought this coin and what price you want to achieve. Then you can sell this coin completely and then buy it again after the price rollback.
if you are a long-term investor you can do that, but if you are a daily trader you need action that is more simpler and faster, you can't write it down on the many coins you bought that day right? You just need to be good at remembering, good at analyzing, and good at reading opportunities to buy and sell
I disagree, regardless of the type of trader that you are keeping a trading journal is critical for your success, after all how are you going to learn from your mistakes if you do not take the time to analyze them, memories fade and if you are a short term trader this is even more common since it will be impossible to remember all the conditions of the different markets in which you traded in a single day, so in my opinion it is not only important to keep a trading journal you should also keep pictures of every market in which you traded, even if all of this may seem time consuming it is something that must be done if you really want to improve your trading skills.