What are the best type of cake boards to use? I am currently using the corrugated ones they sell at the craft store and they are really flimsy.

Are you looking for cake boards for the whole cake to sit on? If so, I usually use MDF boards--they are durable and reusable.

For boards in between tiers, I just use corrugated boards. There are those filmsy ones and there are also thick ones. I actually buy mines from my Fiance's friend's Bakery.