To get rid of any flies that might be around,you can kill them with a Fly trap hidden in a decorative flower pot:
Fill a quart jar with this mixture.
3 cups of water
¼ (one quarter) cup sugar
¼ (one quarter) cup white vinegar
Mix, punch holes in the lid, and set it where needed.
You could just hang rosemary or place pots of them around where you sit, It will cool the walls of your house, too.
"Scents actually have a function ... as protection from insects in some plants or as protection from drought in hot, arid climates (the thick volatile compounds we smell provide a protective layer around leaves). The old English custom of covering brick walls with sprigs of rosemary for cooling has been supported by modern research, which shows rosemary has 74 times the cooling effect of fresh air (thyme has 68 times the cooling effect, lavender 60 times)."
http://www.uvm.edu/extension/publications/oh/oh66.htm
Mosquitos & flies don't like rosemary, thyme, lemon balm, garlic, citronella, the oil of lemon eucalyptus, or Tea Tree Oil.
Make a spray from one or several of those repelling herbs mosquitos don't like, such as mint or lemon balm & add a tablsp dish soap to a gallon of water & spray your bushes with it when you're outdoors.
Use those citronella torches &/or candles.
It's interesting to note that when golfing, some people would put a bounce dryer sheet in their pocket to repel insects.
Plant mint around your house & use cedar woodchips for your walkways & paths... or incorporate it into your decoration or plantings on your deck. Make sure there's no breeding areas for mosquitoes (piles of leaves, ditches, damp spots, etc.) around your yard. That's the biggest cause of mosquitoes hanging around.
This site has an interesting discussion about using Basil, among other things, to help them keep flies away:"I'll second the sweet basil...I have giant Jurrasic basil plants planted around my deck, and we never see flies anymore."
http://ask.metafilter.com/19342/flies
Good luck! Hope this is helpful.