Luggage and bags: Ubud is in the center of Bali set in tropical forest and rice fields, so the mosquitos abound here. You shouldn't forget packing mosquito repellent and put it on, specially at the end of the afternoon. The hotels in Ubud usually provide mosquito coils in the rooms. Also, at night, use long sleeves and pants or longer skirts to avoid bites.
Luggage and bags:
light dailypack for bring your stuffs while go cycling
Clothing/Shoes/Weather Gear: comfy trainers for bicycling
Toiletries and Medical Supplies: toilet papers
Miscellaneous: the most important to bring along whenever you exploring ubud [and all places in bali] is sarung [saroong]. because very useful to cover your short pants whenever you visit a temple. for respect to its place and the worshippers, do not enter with unproper clothes. of course you can rent a sarung in front of the entrance. but most comfy and nice is using yours as we always do :)
Luggage and bags:
Any kind of luggage will do (since they have the USD 3,000/night hotel down to USD 10/night hotel). The lighter the bag is the better..
Clothing/Shoes/Weather Gear: Wear a comfortable foot wear (I use Crocs flats everywhere in Ubud). Light fabric dresses/shirt from linen and rayon is the best for any Bali destination. Light cardigan/light jacket will come handy at night windy time. A sarong (buy in Ubud Market, it's cheap) will come handy too (when you're visiting temples).
And of course, a pair of sunnies.
Toiletries and Medical Supplies: Sunblock is a must.
Photo Equipment: Any kind of cameras will do. But during a parade (ogoh-ogoh or ngaben), be sure to have the tele lens ready.
Miscellaneous: For women who wear their hair long, a scrunchie is also a must. Ubud's hot now, people..