Being the most visited destination in Indonesia, the tourist infrastructure in Bali is quite diverse and fairly easy to navigate. You can easily hail a cab using Grab or Gojek. Grab, however, is easily the cheapest and ideal option to get around as compared to any other service. The taxis are clean, licenses, and the drivers are usually comfortable with English. The local drivers have some resistance towards the service and may tell you that it is illegal, do not believe the same.
Gojek is another app, which works out marginally cheaper than Grab. However, it is currently available only in Indonesian, which is a limiting factor for its usage. You can also book a taxi using the Bluebird App. However, make sure the car is authentic and safe. Normally, Bluebird taxis have the word ‘Bluebird’ emblazoned on their side. Please keep in mind that some areas in Bali have designated drop-off zones, for eg: Canggu. This is done to regulate the cab services and the number of cabs.
As with any other tourist destination, you can hire a car and driver in Bali as well. You can have these at your disposal for upto 10 hours. Often a more convenient option, it is recommended for those who have a clear itinerary of the places to visit at hand.
Bali also has a fairly robust network of local buses that operate on 8 major routes across the destination. These include - Kuta, Legian, Seminyak, Sanur, Jimbaran, Nusa Dua, South Nusa Dua, and Ubud. Each of the routes has a designated ticket and the service is fairly regular. It is an organised shuttle service and is recommended especially for solo travellers or huge groups of friends travelling together.