REWARDS - $200, Respect, Gang Tags collectibles unlocks
You'll see Sweet and Smoke playing some basketball, then Sweet will tell you to go spraypaint your gang sign in some areas. Sweet will accompany you on this mission. Drive to the marker in Idlewood and get out of the car. Sweet will tell you how to spraypaint, so pay attention. You have to keep doing it until you spray your whole logo (you'll get a confirmation that it is done). After Sweet tags the first one, you'll have to tag two more in this area. One is on the blue house directly across the street and the other is the alley behind the first row of houses. Once you get both of them, get back into the car and drive to the next area in East Los Santos.
Tag the first sign, then go towards the next blip where you'll find two rival gang members standing in front of the next one. Target them and spray to temporarily blind them so you can get the next tag. Head towards the red marker and hop the fence. Hop the next fence, turn left and hop onto the roof of the building to find the next tag. Once you get this last one, Sweet will pull up, so get inside the car and head back to his house. Mission done and $200 and respect earned.