I'm sick of getting sick. Give me some tips on staying well and avoiding the seasonal cold/flu's that I seem to always get without fail

For the last few years I've gotten sick maybe 6-8 times each year, usually just the standard cold/flu. It's really annoying and seems to be more often than I used to get sick. My lifestyle and diet is better than it used to be (I exercise and eat well) but doesn't seem to make a difference.

So those of you that seem to be well all the time - do you do anything special? Do those immunity boost juices actually do anything? Do the probiotic yoghurt drinks actually help?

And also I remember reading something on reddit a while back about having a healthy immune system meaning that you actually get sick more often because your immune system is doing it's job. Anyone know anything about this?

Thanks