My house is not visible from the road and our driveway looks a bit like communal parking -which is not but that's another thread . Because we need to keep the access clear for parking it's hard to have a decent house sign near the road to mark it.
I always say "look for the house with the people carrier on the driveway.
Having always been a SAHM I am just about to start a WOHM and so actually for delivery folk etc the car won't always be there any more.
A flag is a a bit "Brexit" but I'm thinking something like permanent balloons for a birthday party 
Does such a thing exist?