How to create a knot for the flat Haori himo with pompom
(Flat haori-himo are rather casual and shouldn't be worn formally)
Flat Himo knot method 1
Take your himo, put them together and fold them at about the width of your hand.
Turn your himo so that the pompoms are facing you. Take the himo at the back, make it loop a the front and make it go between the four himo at the center.(side-view)
Make it go out above the loop at the back.(back-view)
Tighten (side-view) 
(back-view) 
Do the same with the other himo. Make a loop at the front. 
Make a knot at behind.(font-view)
(back-view) 
Tighten and you're done.(front-view) 
(back-view)Take your himo, put them together and fold them at about the width of your hand.Turn your himo so that the pompoms are facing you. Take the himo at the back, make it loop a the front and make it go between the four himo at the center.(side-view)
Make it go out above the loop at the back.(back-view)
Tighten (side-view) (back-view) Do the same with the other himo. Make a loop at the front. Make a knot at behind.(font-view)
(back-view) Tighten and you're done.(front-view) (back-view)The original page where these images came from can be found at Immortal Geisha forum
Flat Himo easy knot
This is the same knot as above but with a somewhat easier method.
Take one himo, make a loop with having the pompom end going to the left.
Take the second himo, do the same as above but have the pompom end go to the right.
Put them together, one loop inside of the other.
Take both pompom ends and gather them together. Hold with one hand.
Take at the middle of the rest of himo, fold it slightly and make it go through the loop.
Pull down so that the pompoms are at the right height.
Tighten and you're done. (front-view)
(back-view)Flat Himo fancy butterfly knot
A fancy knot which looks like a butterfly. Casual of course.
Take both ends of your himo and make the cross at approx. the width of your hand.
Then make a weaving knot like the one for scoubidous. Look at the pictures to see how it's done.
Tighten and turn over.
Make both pompom ends go under the himo at the top.
Adjust the pompoms height, tighten every thing and you're done.The original page where these images came from can be found at Immortal Geisha forum
The original Japanese page where these images came from can be found at Kimonoo.net