Now that I actually own a real maiko han'eri I'm going to give embroidering my own a shot.
I've just bought some white han eri off YJA to try with.
Honestly seems simple enough.
On closer inspection the gold thread seems to be flat gold paper.
I don't know what it is.
I bought some gold thread stuff from Ryu months ago, can't remember what they called it but it's nice and shiny and should do the job fine.
I tried to get some detailed photos on Flickr with measurements if anyone else wants to give it a try too.
I've finally taken the plunge and will get my water lily hikizuri shipped from Crescent Shop.
I've been putting it off for a few weeks because with Australian customs/importing place if the value of the item is over $1000 then you get charged a fee or tax or whatever they want to call it.
My co-worker got me some info about it, because he buys guitar off YJA and they sometimes cost over a grand he guesses the fee will be about $250 so I let it at Crescent shop for a few weeks to put aside money for that.
I can't wait to get it!
Hopefully it should be here in about 2 weeks if it doesn't get caught up in customs