Worth the effort. I did a bunch of travel in Italy, and went through the process several times. Probably easier for me going through an airport
where they're used to it, but really not that difficult. Italians seem to appreciate someone desiring to not pay taxes
In my experience they were real sticklers for having all of the vendor's information (name, address, telephone, and tax number). That should be printed on the fattura, if it's not pressure the vendor into printing one with all of that information. Not legal
in Italy to conduct business without a fattura, and not legal
to have a fattura without the information as that is how the tax man tracks things (so naturally, issuing receipts/fattura without is how vendors try to dodge taxes). Other than that you just fill out the form, get it signed and submitted on departure and collect your refund.