depending on what time your daily reset is.. you get to the tower before that time, like 5-10 mins before.. wait till that time. Go to eris and get bounties, instantly go do those bounties. Turn them in and log out. Log back in go to tower, go to eris and those bounties are there again. Personally ive never done it as my reset time is at 1 am...

that at the reset you get double bounty, something like that