Phone notifications are what helps me not to forget something the most.

I disabled all useless notification and now on my lock screen I only see things I need to process.

I get message from someone that I don't want to reply right away? I just leave that notification on screen.

All reminders, mails and various other notifications (my washing machine pings me when its done) stay on my screen until I do what needs to be done.

This together with using trello as personal scrum board really helped me todo more.