You can trade in ugly clothing for other rewards. The vendor is near the snowglobe marked with a perppermint candy.
Presents contain 3 minis, x-mas dyes, and weapon skin tickets. You can also buy the weapon skins on the gem store if you don't get a weapon skin ticket.
The event's going on now grant mini's you need to craft. If you do all events in each city you will get enough mats to craft 2 of the 5 mini's available. You can also just buy them in the gem store under mini's.
When tixx reaches lions arch he will give everyone a gift.