I know everyone recommends Avon Skin-So-Soft but I have been REPEATEDLY sucked into trying it, a number of times, in three different states and one canadian province, over the past twelve or so years, and NOT ONCE has it done squat against the local types of mosquitos. Alas
Please do not set aquarium/baitfish/ornamental-pond minnows "free" into a local stream, oftentimes they are not native and you don't want to get a big problem started, and moreover they are quite often carrying serious diseases and parasites (even if they look ok to you) and a lot of natural fish populations have been really decimated that way :/
Bt mosquito dunks/granules work real well in a fishless pond, when used as directed and when you put them in while the skeeter larvae are still smallish.
For those who (like me) have a serious big mosquito problem, though, remember that virtually all of them are coming from ELSEWHERE, not on your property, so there is not a great deal you can do about breeding other than (obviously) not giving them even *more* breeding grounds.
I have been trying that garlic-oil/garlic-extract spray this year -- if applied at 2x label strength (which is totally safe, just more expensive) and rather heavily, it does seem to be useful in discouraging HEAVY congregations of our mosquitos from particular areas. You might give it a try.
There are many many dozens of mosquito species in North America, though, with very different habits, and no repellent works equally well on all them.
Good luck, have fun,
Pat