Hey am from Uganda and am planning for a travel in japan on a visitor visa and among the document asked are the travel itinerary and personal tax return . How best can I prove my travel itinerary when it comes to hotels and flight?
It's generally not advised to book your flights, hotels etc before getting the visa confirmed.
You can simply provide a list of the expected dates, locations, maybe activities and costs per day (estimated). The idea is to show you have a rough idea of a plan, and you know how much it might cost, and the tax return will help show you're likely to be able to cover it.
If staying with or visiting friends, list them too, as it shows you've got contacts there too.