Here's a guide for 'legal' ball tampering

The fielders with quick arm and the spinners bowling from other end play a key role in maintaining the rough side of the ball. The fielders throw the ball in one bounce to the keeper, trying to land it on the rough side. The spinners on the other hand, try to land the ball on the seam or the rough side, which also helps them extract more turn.

Sweat, the other component apart from saliva also plays a crucial role in the art of ball making. ‘Vaseline’ and ‘Lip balms’ take centre stage, replacing mints and lollies. But here again they are only catalysts, players cannot directly apply Vaseline on the ball to make it shine. (Credit: @moonshop90)