As Venice:
- Researching Optics awards a free MoV
- Going Liberty can get you two free MoV's (one from the settler SP, one from closer)
- Leaning Tower of Pisa can get you a free MoV
- Going Commerce can increase MoV generation
- Build Gardens and National Epic in Venice and lock specialists into merchant slots for more MoV's in the early going
- Purchase MoV's via faith if you can generate enough faith
- Bear in mind, puppeted cities naturally prioritize gold; purchase gardens and buildings with merchant specialist slots in any puppets you can
*** A lot of these hints were mentioned in other posts already, but these are all things I've tried in my goofing around as Venice thus far. A key question you should also ask, however, is:
When do I switch from puppeting with the MoV over to using his double-strong Trade Mission ability?
This is the question I still struggle with. Eventually, you will reach a point where the Trade Mission will be a possibly better option, as once you have enough trade-routes up (via your UA, you get 2x as many of them, so this will happen faster as Venice than as anyone else) you will have so much gold available that it may be more economical to buy a large army and take a few puppets that way.
I'm still finding my way through Venice to figure out at what point the MoV should just do super-powerful Trade Missions. ***