@NoTechi, it really depends on your needs. I suggest that you engineer a solution based on exactly what you're looking for. For example, if your door lock switch is accurate enough for your needs to determine whether you are present, just use that in your rules and it should work just fine.
If you're finding that you use a combination of items together often, it might be worthwhile to create a virtual item or items which is managed based on the input of your lock switch. For example, say you also have a bedroom light that you keep on when you're awake. You could create an Item IsBedTime (or whatever you feel it should be named). Then create a rule which takes your presence switch and bedroom light states as triggers. If you are present and the light is off, change the IsBedTime state to ON.
By using this method, you can start by using your individual items in any rules you have. Then, if you find that the rules are getting difficult to understand, you can create virtual items that represent common states you would see. You can do this whenever you feel you need to, there is no rigid requirement for determining when to use this method.