Depends which lane you are in.
As a jungler, try to camp the lane who you'd have the most effect on or is closest to being relevant. For example if you've got a vayne bottom, you might want to camp bot and hope you guys can survive to the late game. However the downside is if the enemy jungler counter-ganks your team probably can't 2v2 or 3v3 the enemies.
Split pushing is an option if you picked the right champ and have teleport.
As an ADC or mid laner, just farm up CS without dying and try to be relevant.
As a support, depends who you are playing. If you are leona, you are screwed. If you are annie, soraka, blitz, or a few others who stay relevant without really needing items you might be able to slow the bleeding.