From my play through without a save I did not find a way to do it with a fresh profile. My first play through I played with my mass effect 2 save. If you are asking because you do not have a save I would suggest:http://www.masseffectsaves.com/
They have save files for both mass effect 2 and 3 and allow you to choose paragon, renegade, or neutral. It also allows romance options and each user provides all their info for the save. This could help out a bit.
Good Luck and enjoy the game. If the ending bothers you like it did many, remember there is a DLC coming Free of charge to add to the ending.