Candles Affect Enchanting

A (relatively) simple idea: using different colored candles in place of book shelves around an enchantment table gives better odds of different types of enchantments being available. 

Red ~ Fire Aspect

Blue ~ Aqua Affinity

Orange ~ Fire Protection

Brown ~ Protection

Yellow ~ Smite 

Green ~ Fortune

...and so on and so forth. This would necessarily require that you won't have the highest level enchanting table, as the candles would replace bookshelves in the frame.