"To empty this residual urine, the reported most effective method is called “urethral milking”. To do this, take your index finger and place it in the area between your scrotum and your rectum. Apply gently pressure and move your finger forward, up over the scrotum, and to the base of your penis, effectively draining any liquid that remains. Do this 3 times and then ‘milk’ your penis, gently squeezing from the base to the tip." - https://menshealth.com.au/how-to-stop-pee-drips/

Personally, I only do it once and it has worked wonders. Lmk if you need a visual aid(Unironically, that method fucking changed my life and I think it is so great that dads should be passing it on to their sons).