1. Flame Rift does not work in U/R. Use Flame Rift for Sligh. In U/R, the primary purpose of the cheese is to get rid of opposing creatures, something Flame Rift cannot do.
2. When playing U/R, remember the key is CONTROL, not aggression. Use your bounce, burn and counterspells to prevent your opponent from playing or keeping anything on the board which can allow them to win.
3. When playing bounce, spells which bounce multiple permanents are better. Examples include Wash Out, Aether Burst, Rushing River or Capsize (because it repeatedly once you have 6 mana).
4. Counters which cost 1 to 3 mana are best. Examples: Counterspell, Mana Leak, Dissipate, and Forbid. Spells which cost 4 or more mana would ideally be "free" like Foil or Force of Will, and even then there should be no more than 2 to 4 of them.
5. Tailor your spells to match the environment. People are more the weenie type? Use Pyroclasm, Fire (and Ice), or Breath of Darigaaz. Larger creatures? Use Flametongue Kavu, Volcanic Hammer or Lightning Bolt. Token creatures? Bounce will kill them just as easily as cheese can.
Here's an example of a favorite U/R build of mine:
Lands: (24)
2 City of Brass
12 Island
10 Mountain
Creatures: (2)
2 Firestorm Hellkite
Cheese: (10)
4 Lightning Bolt
2 Breath of Darigaaz
2 Arc Lightning
2 Flametongue Kavu
Counters: (12)
4 Counterspell
4 Forbid
2 Force of Will
2 Mana Leak
Bounce: (2)
2 Capsize
Card-Drawing: (10)
4 Whispers of the Muse
4 Accumulated Knowledge
2 Fact or Fiction
Tell me what you have, and I can suggest substitutes if you're missing any cards.
