As people have mentioned already, its definitely about forming habits. 2 things that are helpful in doing that are lists and alarms. My understanding is that we forget things because our attention, at that moment is focused on something else other than what we are supposed to be doing. We have fantastic alarm systems for getting nutrition or getting rid of waste materials from our body - but alas nothing for products of our thoughts. Lists are great tools for refocusing thoughts. So start with lists. Put it contextually, like on the back of door or the place where you keep your shoes if you want to remember what you should leave the house with. Then add alarms to add the space and time awareness. Check some IFTTT recipes or set location based reminder on your phone to go over the checklists. What would be challenging is refocusing from the current context to what you are supposed to when the alarm goes off. Don't be too harsh on yourself - remember its a leaky bucket by design :P