I've seen too many 'handwritten' fonts with duplicate characters sitting next to each other, and therefore spoiling the whole idea of the design. I decided to go a different route. I first made the basic character set, and then worked out by handwriting those natural ligations with two or more glyphs, and incorporated those as OpenType ligatures. With enough three-glyph ligatures complementing basic ligatures, the over-all effect came pretty close to real handwritten text.