Hey, figured I'd post these here because why not. Here are the highlights of the moments we hit 75 during closed beta! Both are from my perspective since I was streaming the whole thing. And pardon the quality - going off a cheapo HDMI capture card because I wanted to stream to Twitch and not Mixer 
@Syrus-White Most likely kept EXP boosters popped and did every single Urgent Quest that popped up while prioritizing the Daily Quests before running Client Orders that yield the most EXP.
Doing all the Arks Missions and grinding AQs then UQs and having friends or friend partners filling out your party for the extra boost also helps.
Also EXP boosts stack with triboosts, as do the other boosters as each one gives a different buff. Least it worked that way in the Japanese servers. I wouldn't know if it does on the NA servers. Also you could stack up to three of each boost to extend the time limit so you don't have to worry about them running out before you use a new one, though if you use a new one too soon, you'll waste the time boost.
It was mostly forest AQ (since the others were locked) and farming PSE bursts.
Urgent quests are really good exp lower levels but kinda drop off a bit later (at least with our current selection of UQs). Once you hit 40, AQs wind up being super good experience the whole way through, especially if you can trigger PSE bursts with a bit of luck and a lot of quick killing!
@Karma Thank you. i will be shifting my focus to AQs. Did you do them solo or did you have a team with you?
AQs are definitely better with a team - the PSE bursts only spawn one enemy per player, so having a full party of 4 people will give you 4 constant spawns to work with during the bursts! They're a bit underwhelming when you're solo and just killing one enemy over and over again.
@Karma Yes. I realize that now. Thank you for your input. I managed to lvl a force to 75 in about 2 days. I'm currently working on my second for techer but as you may know the servers are down. my mission, get to lvl 75 tonight.
