Last year I used an older rusty bird bath as a offering altar for the Spirit of Water, filling it with some water and putting a few flowers in it to float and provide decorations throughout the Summer months (tossing it out when the water grew stale or the flowers withered).

Not sure if it helped but I always seemed to get some rain when I needed it. Plus it was a nice addition to my garden decor.

I ran across this DIY Mosquito trap idea written by the Washington Gardener:

DIY: Mosquito Trap Water Garden

Basically have a water filled container, add some organic matter (like flowers) because mosquitoes seem to prefer laying their eggs in water with some organic content (but not just dirty water), add some water soluble BTI, which is a bacteria that is only toxic to mosquito larva, refill every few weeks or after a heavy rain.

Source of BTI: Mosquito Bits

Looks like this works on fungus gnats too.

With the rise of tropical diseases now become more common north into the domestic US, this seems like a good and easy solution to any mosquito problems. Remember to drain any spots that collect water (like old planters or buckets left out).