You should decide first to focus on a strategy. Try to enhance it with the maximum number of each card you choice. Consider the people who you play and their strategies.
Remember that the goal of a good UB deck is to bother everyone. So don't worry about growing your creatures. Better to focus removing blockers or you should try to cross your creatures through their defenses.
This was mi first UB deck:
http://deckstats.net/decks/22258/130487-control/en(obviously I don't have any Tamiyo but it would be awesome)
I hope this clarify the issue of "strategy".
And at last advice is: Play, check other's decks, make questions and play