How to decorate gingerbread cookies

[Anonymous]

So DS and I are planning to bake and decorate gingerbread cookies (Xmas trees) to send to my husband who is working overseas. I have a box of several small tubes of icing in different colors, and several types of sugar sprinkles. My question is, how do I fix the sugar sprinkles to the cookies? Some of the sugar sprinkles are very small, and some are larger snowflake shapes. Can I just use regular icing (icing sugar and water) to stick the sprinkles to the cookies, or is there some other technique I should use, bearing in mind that the cookies may get knocked around a bit in transit?

[Anonymous]

If you sprinkle right on the cookies while they're still warm, they'll probably set without icing.

otherwise, do the sprinkles on top of the icing.