Rule number 1:
Always have a clean bedroom and a well made bed. Every else in life follows after this rule. Note that I've had this rule even before Jordan Peterson's book. The reason why I put this as number 1 is because it's grossly unlikely that you can do anything in your life if you can't even control the one room that you're supposed to have ultimate control over. An easy way to maintain a clean bedroom is to keep the number of possessions as small as possible, if you can relocate your possessions, hobbies, etc. to another room, take the effort to do so.