Much convenient and easier if you book by yourself.. Do some research and it should be a pretty smooth trip. For certain excursions you can book thru local agents ( Cheaper ) or you can book thru portals like Viator.com
Would suggest to book on your own.
1)Book flight tickets on Skyscanner.
2)Book hotels on trivago/mmt/expedia/goibibo/hotels.com/agoda/booking.com
3)Check sightseeing tours on viator/isango/grayline.etc.
I traveled to Bali in 2016 with my siblings, we booked a villa through Airbnb & did a bit of research. We didn't encounter any problem, as generally people of Bali are very sweet & helpful. We were staying in Seminyak, which was pretty good & happening place. For all the 5 days in Bali, we hired a cab referred to us by the owner of villa, one can also book a bike easily.
Would suggest to book on your own.
1)Book flight tickets on Skyscanner.
2)Book hotels on trivago/mmt/expedia/goibibo/hotels.com/agoda/booking.com and Airbnb
Spend your time reading trips on bali by tripoto writers and other blogs, check youtube for videos shared by famous video bloggers. its a safe place and happy travel.
You can book on your own as well as through packages . Both have its merits and demerits depending on the time you have. - People who are expert in planning will be able to suggest you best things and things which are suitable according to your requirements. If they charge for the same, I think its fine. Many times you get better pricing for the same wrt flights, hotels, etc. - Now, if you book on your own that is another fun thing where you will explore on your own and take risks which should be good and it can be cheap considering you don't pay any agent. * Many people follow youtubers or forums without understanding what they actually for themselves and try to emulate them (personal point of view - not applicable to all). Don't follow a fixed thing, booking by own or booking through some company, get it planned/ customized based on your likings.