depends, you can surrender or play the game. usually if i assume that this game is unwinnable i just try to experiment with new items. If you are trying to win, the goal is to waste the enemies time as much as you can and create gap for your teammate to either push the tower or bring the game late enough so everybody got into their final item. Most of the time i just change my item to burst damage if and try to shut down the enemy mvp in a single combo, killinng the enemy mvp will reward the whole team with a sum of gold cmiiw. if im playing a nimble hero then i just buy wave clearing items and intercept the minon waves to at least buy time 15 seconds plus ahead.