This is ValoR and I'm going to give tips on how to play S&D but not like a noob
PRE-GAME: Sort your class out first, don't use a noobish class. (NOTE: These are only things for low level people, if you want to use anything more powerful, then feel free to use it) Use:
A high powereed assault rifle, Like the TAR or the SCAR, with silencer.
A shotgun, SPAS or AA-12, the Striker isn't very powerful from a range, sporting 3 hit kills
Claymores or Frags seem to work for covering behind you and clearing out rooms or bomb sites
Smokes can be a bit of a giveaway but combined with Cold-Blooded, no-one will notice you
Perk 1: Bling or Sleight Of Hand, Bling if you want something more than silencer, or Sleight Of Hand because you hate dying while reloading.
Perk 2: Cold-Blooded or Stopping Power, Cold-Blooded to get past thermal or ide from killstreaks, and Stopping Power for if you get found and Cold-looded didn't cause enough damage
Perk 3: SitRep or Ninja, SitRep to see Claymores/C4, even better for hearing the enemies with the Pro version, and Ninja for being steathy.
Deathstreak: Final Stand for escaping areas WITH a chance to live.
ROUND ONE: Anyways into the game and your team usually doesn't do anything, but get your team to split up, 2 to Site A, 2 to Site B, and 2 to try and get behind them. If you only have 4/5 have only 1 /no-one going behind them. Now if you are DEFENDING, then if you are at a bomb site stay in a place that isn't easily found, but the bomb is still in sight. If they plant at the other bomb, then the guys there aren't paying attention. DON'T GO RUNNING THERE, you will most likely be shot. Use your frags (If you had them) to clear out any possible hiding places and look around first before defusing, if you are certain there is someone still alive and isn't AFC (Away From Controller) then look around and kill him, then defuse.
If you are ATTACKING, then if you are NOT planning on planting the bomb then go with someone to one of the above places and kill everyone. THERE WILL ALWAYS BE A CAMPER so watch out. Then go and assist your teammate planting the bomb at either bomb sites, assuming the other one is cleared or you didn't die, and stay in sight of the bomb.
ROUND 2: DEFFENDING: DO THE SAME! Just because they planted it at a bomb site, doesn't mean they'll do the same one again.
ATTACKING: DO THE SAME AS WELL!
ROUND 3: ALL TEAMS: DO THE SAME
ROUND 4: You have switched teams so do the different way than you have just done.
ROUND 5: You should have won the game, unless no-one was listening to you and all died. If my class is rubbish, you didn't have to use it. That was only a suggestion. If you have better classes then use them.
ROUND 6: The usual.
OVERTIME: DO NOT RUSH BECAUSE YOU WILL BE SHOT. Move up slowly and don't go into the open.
IF YOU ARE PLAYING HORRIBLY BECAUSE OF CAMPERS ETC. THEN LEAVE. Campers are the shorter version of nooby-little-gays.