I began watercolour lettering when I forgot to buy a birthday card for my daughter. Overnight, I put together some presents, borrowed her watercolour paint set and made a birthday card. It simply said "eight"... but I formed the "g" into the number "8".
Simple I know and since then I have practised daily, watched tutorials on youtube, read books about lettering and found much inspiration from others to keep going. You can never learn enough!