Smart Card for Edinburgh

https://lothianbuses.co.uk/tickets/ticket-options
loads of options on this website. personally I think your easiest option is to buy a day ticket on the first bus you use ,available from the driver and you need the exact fare (no change given).so £4.00 per person per day. just hang on to your ticket and show it to the driver of every bus you use.
BTW the bus service in Edinburgh is excellent.

Uncle Gus: Thanks for your reply. We will likely go with that option since one of the few days we will be in Edinburgh will be taken up with an all-day tour.

I use the buses a lot in the city but I have a National Entitlement Card as I am now 60 years old and get free travel on any bus service in Scotland. Btw the day ticket for the bus also allows you to use the tram though not all they way to the airport. You can download the Lothian bus app to find nearest bus stops and when buses are due but most of the stops in the city centre have Sat controlled information boards letting you know how long till the next bus.If you need any info on any particular route just ask but I will be out of the country from the 5-12 August with little access to internet (I am away to the Czech republic on a walking holiday)
Enjoy Edinburgh and have fun on the buses.

Thanks--enjoy your travels.

I'll second UncleGus's recommendation for the day pass. I've used it so many times. It's easy to get. It's flexible and as already said the buses are great in Edinburgh.

Pam