I came up with this pattern for the Queen's Diamond Jubilee in 2012 & the 60th anniversary of her coronation which is in 2013.
It has 4 different types of diamond patterns with a diamond edging which is grafted on afterwards. You can always leave this off if you're not happy with grafting.
Gauge is not really important as it's a scarf, but if you alter the type of yarn or needle size the requirements will vary.
I used 350 m of 4 ply to knit the teal coloured scarf & maybe a little less for the cream 2ply one.