Shrink pores

There's nothing you can do that will permanently shrink pores.  Well-- not that I've heard of.

But to prevent pores from getting even bigger, always be sure to use all these products:

1. Cleanser
   
2. Exfoliator - scrubs off excess skin that may clog pores
   
3. Toner/ astringent - cleans out the leftover dirt and grime from cleansing
   
4. Oil-free or noncomedogenic (non-pore clogging) moisturizer to maintain the pH of your skin.  

Moisturizer is really important because without it, the toner/ astringent will leave your skin too dry, causing excess sebum (oil) production which will further clog pores.
To temporarily shrink pores, you can use a face mask (I've heard that egg whites work too?  I need to look that up!) or using pore strips.

Here's another one I found online:

Combine equal parts orange juice and water and swab the mixture across your face (avoiding the eye area) with a cotton ball. "Leave it on for a few minutes, then rinse," suggests Rebecca Ugalde, editor of Women's Health's Central America edition.

Source: Women's Health