I would use a light concealer down the bridge/end of your nose and a darker one at the sides. Hopefully that will give the illusion of a shadow. If your nose is very red there are special shades that have a light green tinge, which takes away a red look. Finish with powder following same concept as above, this will stop any sheen, which will make your nose look bigger.
The shadow thing may or may not work - it is a concept based on how to make a cleavage look bigger - you use a darker powder in the middle, thus creating a shadow. I imagine reversing this concept for the nose may have a similar effect?!?
On a lighter note:
Eye Eye Jack, 'avn't seen yer for ears and ears, but I still nose yer!
Sorry, I couldn't help myself...........