I will be in Venice at the end of August with my boyfriend. We would like to take a gondola ride but in a somewhat quieter and more rustic (read romantic) area than just e down the Grand Canal. I would like to go under the Bridge of Sighs if possible and the more bridges the better. I have been on 2 previous gondola rides, but I didn't have to arrange those.

I read a suggestion for boarding a gondola at Campo Santa Maria del Giglio near the Gritti Hotel, but don't know if it is a good one.

Any ideas?

Try Campo San Barnaba - there are generally a couple of gondoliers hanging around there.

Try the Gondoliers at the landing area opposite St Marks Sq. You are right by the Bridge of Sighs and can arrange with them to take you across the City. Whichever route you use, there are lots of bridges.

Expect to pay around €80 for the ride.

Last time I checked, the Bridge of Sighs was still under scaffolding, so you might be disappointed with that. Gondolas will not generally take you down the Grand Canal during the day, as it's so busy - you might cross it, or enter it from one canal and leave it by the next. There are many gondola stations to choose from - there is one right behind St Mark's Basilica, on the same canal that the Bridge of Sighs crosses.
There is an official rate, but if you walk away when they say what it is, I've heard that they will 'negotiate', as there are more gondoliers than people who want a gondola ride. But make sure you agree on the duration of the ride before you get in the boat. A Venetian hour is usually more like 50 minutes.

Another good spot to start is Campo Santa Maria Formosa.

Good idea to avoid the Grand Canal--it's better seen from a vaporetto. The gondola is wonderful for getting a "canal-eye view" of the city along smaller canals. I especially like the gondola when the tide is low so I can see more architectural details.

Thanks for the advice. I will also select a route that does not involve the Bridge of Sighs.