Answer: o perform by gently rolling the testicle between the thumb and fingers
feel for any lumps or bumps along the front or sides
look for irregularities on the surface or texture of the testicle
Explanation: the first 2 are opinions. You can do it in the shower or after but it's not part of the procedure. And the second one, yes it's recommended for gentlemen after they turn 30 to do it regularly but a young guys should do it once in a while just to check for any abnormalities. Hope this helps.