ive had about two 30-0 FFA games and around like five 30-1 and so on.
my kilstreaks are spy plane, chopper gunner, and attack dogs. if i get a spy plane, i dont use it right away cuz i wont have enough time of spying to get me to chopper gunner, so i wait til im at about 5 kills, or if i die, i get spy plane again so now i got 2, then i can use the 2nd when my 1st runs out.
and another thing is to stay to the edges of maps not in middle, also when u get chopper gunner, WAIT, and get attack dogs, release them, then click your chopper gunner, because now'a days u get shot down easy, but when u have attack dogs out it helps alot because they kill the rpg noobz aiming at your chopper
usually after im succesful in getting all my kilstreaks, i finiish the game to 30 kills in about a minute