As an alternative to the crowded streets of Venice, Milan and Florence, have you considered Verona? It's the city of Romeo and Juliet, with beautiful of squares and romantic buildings. There are direct flights from Glasgow.
Thomson Flights (http://flights.thomson.co.uk) advertise a direct service from Glasgow International to Verona. This can be as part of a holiday package, or flights only with fares starting at around £148 return.
An alternative option is to travel with Ryanair (www.ryanair.com) from Glasgow Prestwick to nearby Bergamo. Fares start at £29.99 outbound and £20.99 inbound. These are the tax-free fares, so need a little searching out. Be aware that Ryanair has a long list of possible additional charges (their website lists more than 20 categories!) so be very careful when booking your ticket.
Juliet’s House is on the Via Cappello, identified rather vaguely on the assumption that the Cappello clan (before they got into football management) were the family Shakespeare turned into the Capulets It’s a pretty 14th-century house with a balcony. Visitors are encouraged to seek luck in love by rubbing the bronze statuette of Juliet.
Real, as opposed to fictional, history is on show at the Roman Arena, not smaller than the Colosseum in Rome, and now used for the rather less bloodthirsty spectacles of opera and classical music. Summer evening shows in this amazing setting are usually memorable highlights of a Verona visit.
Before the flights back to Glasgow, enjoy a stroll with the locals. The pre-dinner ritual involves a cocktail or glass of Prosecco, along with a few olives, before finding a table at one of the city's impressive restaurants.