You will shop - promise! The variety of shopping on the island is huge, and the prices are reasonable, so take a big suitcase, but take it nearly empty and only worry about your weight allowance on your return flight.
The weather is warm - year round – there’s no need to take bulky jerseys, coats etc.
Laundries are everywhere and are very cheap and efficient – they wash and iron as a same-day service, or overnight, for a good price.
Whether you're staying in a hotel or a villa rental, the following items are a "must pack" for Bali. Other than the obvious (I’m sure you can figure out for yourself how much underwear you’ll need and that a hat/cap is a given!), I highly recommend the following:
You will need a sarong – either for the beach or to visit temples (where a sarong and sash are compulsory. The sashes can be hired at the temples for a few rupiah). Men will also need a sarong and sash for temple visits. If you don’t have a sarong, Bali must have most of the world’s supply, so purchasing one when you get there will be both incredibly easy and incredibly cheap!
Pack one cardigan - or long sleeve T-shirt - and a pair of lightweight pants. There can be cooler evenings, particularly inland, so it doesn’t hurt to have something a bit warmer just in case.
You must have a t-shirt/shirt that covers your shoulders if you want to visit any temples. You can’t go into temples with uncovered shoulders (this is strictly adhered to).
On the shoe front...flip-flops and more flip-flops. There’s a reason why the whole of south-east Asia lives in them – they’re comfortable, cool, easy to clean (you will occasionally walk through mud, sand roads, rice paddies etc), and will survive rain without any damage. And – an important point in Bali, where it’s polite to take off your shoes whenever you enter a shop, some restaurants etc – they’re easy to slip on and off. Again there are plenty of places to buy more if you need (Havaianas have a great range and a lot of outlets on the island).
Also take one pair of pretty sandals (preferably flat - the pavements can be treacherous in places) for evenings, and a pair of walking shoes (that you don't feel too sorry for), if you’re wanting to climb a volcano, walk through a rice paddy or go cycling.
Take a casual dress for evenings, but there is a huge choice to buy when you’re there. Cool, flowing dresses are the best way to go (it gets hot!)
A few swimming costumes - of course. Contrary to some misconceptions, Bali is not the place to go topless on the beach, so bring both halves of the bikini! There are plenty of beautiful cossies to buy on Bali but only in the south (Seminyak, Kuta, Legian, Canggu etc). The minute you leave that area you won’t find them anymore.
Be like my Irish friend, Jacqui, who travels nowhere without her brolly (and her own tea!) and take a compact fold-up umbrella if you’re intending to be there in the rainy season (Jan-March).
On the medicine front there is an excellent chain of pharmacies in the south and Ubud (Guardian pharmacies) which have everything you will need. They have many branches, and qualified pharmacists at each branch.
There are a lot of medicines that are available over-the-counter in Bali, which might need prescriptions in the west (including some antibiotics), however it’s difficult to know which ones they are until you’re there. In more remote areas you will need to search for a pharmacy (or else the local clinic which will also dispenses medicine), so it’s probably best to pack what you need.
Also pack an international adapter if needed. You can buy the adapter (such as the one below on the left) at the bigger supermarkets throughout the island. The voltage on Bali is 230V so you can use your appliances if the voltage in your country is between 220 and 240V (which includes Australia, all of Europe, South Africa and most of Asia but excludes the US - where 110–120V is used). The plugs, adapters and outlets look like this:
Happy packing and happy holidays!