Get the right gear before you try to fog your yard for insects. Any yard or lawn care store should carry insect fogging equipment or will be able to refer you to a store that carries that type of gear. Next, you need to get an insecticide to use in the fogger. Look for products that have some form of pyrethroid as one of the active ingredients, an effective insecticide for killing mosquitoes.
The time that you fog is almost as important as ensuring that you have a high quality pesticide in your fogger. You want to fog when the mosquitoes are active. Whatever time of day you have noticed the thickest swarms is the best time to get out there and attack them. This time is typically dusk. Otherwise, dormant and hiding insects might escape the brunt of the attack and survive to feed on you and your friends the next day.
Ensure that you take all the appropriate safety precautions before you begin to fog your yard for insects. Don't let the pesticide come into contact with your skin; wear gloves and a work jacket or overalls. Eye protection is very important because a breeze could easily blow the chemical back into your eyes. Finally, a protective breathing mask is required so that you don't inhale the dangerous pesticides.
Insecticides are not a long-term solution to mosquito populations in your yard. They offer short-term control that gets the mosquitoes down low enough for you to work in your yard or to enjoy some time around the fire. Fogging should provide you with at least a few hours of relief from mosquitoes. In a best-case scenario, a few days of relief might be provided. However, rain or watering your lawn will wash away any traces of the insecticide and the insects will likely return.