I've found this difficult as well, my mother always jumped right to antibiotics and it had some pretty clear long term consequences.

My approach with my kids has been to use antibiotics only if there's no progression (better or worse). I figure as long as it appears the immune system is doing its job, that's enough for most cases.

So far, we've given our 3-year antibiotics on two occasions. Once for an ear infection that wouldn't clear and for when he had pneumonia.