I use masking tape, its softer than cellotape and doesnt leave sticky black residue when you take it off, so I put abit over my watch face saying..what I need to remember. Sometimes use my mobile reminders but careful not to put 2.00pm in because if like my phone its 1400, cos if i put 2.00 it ends up AM. Diaries are great until you lose them in a rush. If you drive masking tape your steering wheel (collect milk on way home, get petrol, pick children up from there mates house, not school) also I leave masking tape on popular things I touch alot at work/home, like on edge of my coffee mug so when I go for a sip, tape is in the way. Tape on the mirror, tape on the remote, cross the TV etc. sometimes its cheaper then packs of post its!