Screens are good, you might even want to get those Orient style mosquito nets over your beds. Aside of looking quite romantic they also are totally nonpoisonous. Air intakes should also be kept dust free, moist dust is a perfect nursery for many insects.
Citronella has been claimed to be a quite harmless natural repellant, but candles containing it are only meant for outdoor use which makes me a little suspicious. I wouldn't spread any chemical, natural or artificial, on a baby's skin, only on clothes. We once had fabric stickers soaked in citronella oil, used them on doorways, clothes, bedposts etc. The plug-in thingies have been reported to emit something not so suitable for children.
I just heard on the radio that about 10% of people seem to tempt mosquitos more than average. Some foods might make you smell worse in the nostrils of mosquitos. Also, check your personal hygiene products if their odour mixes with your very own substances to a love poison to mosquitos.
Vodka is good for mosquito blisters, both externally and then also internally used. The latter only for adults when they don't drive.
Insect eating plants might give you some sadistic pleasure moments when feeding mosquitos to them.
I have a handbook from the 50's recommending mixing DDT to wall paint to avoid insects in the food locker... I also recall we had some repellant which was tested in the swamps of Vietnam. Apparently the active substance would be prohibited by now. I'm still normal
