I designed this trap to screw on to a standard 16 or 20 ounce pop bottle. It's got a recessed, narrowing opening just like most other bug traps, and there's a keyhole for hanging it on a drywall screw. The threads are "PCO-1881" and should fit many other containers.
There's also a funnel to print. You can use this to fill the trap, some folks have also postulated that it makes it easier for pests to find the opening and enter the trap.
Some sites recommend covering the traps with a sock, so that they're dark and welcoming to pests. It seems to work on spiders, but hasn't changed my results with mosquitoes as of yet.
I have successfully caught bees and flies, but I haven't figured out the right bait for mosquitoes yet. If you have something that works, please post it!
So far, I've tried:
sugar water with yeast (brown and white sugar)
stagnant pond water
gatorade (has electrolytes like human sweat)
rotten orange juice
all of the above with a spritz of cologne/perfume
all of the above with yeast to produce CO2