Give money to the Liberals (here) or NDP (here). In each year, the first $400 political donation you make gets you a refund of $300 on your taxes. So why not give $400 now and $400 in January?
I don't know if does any good, but you can join a Facebook group or sign a petition. It's really important to write your MP, newspaper, etc.
But a special thing that we Liberals have to do is think very very hard about our leadership choice in May. We made a terrible mistake last time. In this post I'm not advocating one way or the other (cover one eye if you can't avoid seeing the photo on the right - this really isn't an endorsement this time). I'm just saying: whoever you now support, put that aside for a moment and try to think objectively about who would be the most qualified, capable and effective as party leader and the next PM. We need to be more responsible and rational this time around. No more do-overs.