Before I say anything I'd just like to say I had my Titan at level 20 before I was even halfway done on Venus. Not trying to brag, just showing how the rules below got me there. 1) Play every story mission on heroic, the bonus xp really adds up. This also goes for everything else that can give an xp bonus. If you have the choice of +2400 xp or +4800 xp - take the ladder. Even if it's harder, even if it's impossible, never skip out on bonus xp. 2) Before you go anywhere, see if you can do any bounties while your there. You often forget about other things like bounties if your too focused on doing missions. By going over your bounties before you do a mission you will remember to do them while you do other things. 3) Keep your guns and gear up to date and change it every day if you can. It really helps you get motivated to level up your character if you need to level up your weapons and armor constantly. Make sure to disassemble your old gear, even if it feels wrong. After a few times you barely even notice your doing it and you'll find yourself going that extra mile to get +100 xp (which is good btw). Hope it helps

Just do story missions and when you get to lv 5 start doing all the story bounties you can and when you finish game you will be lv 19, aso if you get friends to help you do story in hard mode for more xp

1)Earth stroy missions 2)crucible till level 14/15 & Bounties 3)Moon (heroic mode) and Bounties 4)crucible till tull level 17/18 5)Venus (heroic mode) and bounties 6)if you haven't reached lvl 20 yet do strikes. That's how I did 3 new titans in 5 days ;) If you want to go slower do mission and crucible only dividing your time though days :)

There is no real rapid way unfortunately. I have just finally finished my third character as I cbs for a long time lol. Lots of county's and missions really

It's about 6 hours to get through the storyline and hit 20 while doing bounties.