Start with 2 pairs of walking shoes, raincoat, and absolutely necessary toiletries (they have stores there, but products are different and OTC meds very different and pricey). Realize you are likely to buy souvenir t shirts (no one will know if you wear them, wash, THEN give as gifts). Laundry will be easy in the castle, but will take time away from fun before then, so take a week of undies and socks. It is OK to be seen wearing the same thing more than once. Try to do without electrical stuff like hair dryers, curling irons, etc. or post comments here and figure out sharing. They are heavy, need converters, and tend to die. Go with the 'natural look.' Just wait until you see me...(ugh!)
Put all prescription meds in original containers in your carry on. Also in your carry on put in a light change of clothes-unders, socks, maybe t shirt and your one pair of shorts for emergencies on the plane and the unlikely event they lose your luggage, I recommend ear plugs, maybe a sleep aid, and something to do (that doesn't have to connect to the Internet, it is pricey to have wifi on the plane). Maybe eye shades and pillow-you will feel better if u nap in the plane. Wear slip on shoes, no jewelry, nothing metal, maybe a money belt, on the plane. Stay organized with passport, id, pen, etc handy.
Weigh your bag - max is 50 pounds and overage is something like $75-$150 each way. One checked bag and one carry on is all that's free- you have been warned!
Leave room/weight to bring home treasures! Ask Lee about the tea sets he brought back!
Send or post questions if you have any and I will try to help!!