what is the best technique to restart a new game?
should i delete all sprites an images set physics off the go to line
#1 of the code??

please share your technique

I think it depends on the game type. On some games it's better to delete everything and start again, on others you just reset the positions, forces etc. and that's enough.

A good idea is to start your apps with two functions: INIT() and FREE(). Each time you add some resources, delete them in the free function. Make this your mantra, and you will find you seldom have resources hanging around for the next session of your game.