leveling 45+

whats the best way to level 45-50?

Roulette and beast tribe dailies at this point of leveling.

I did GC levequests, roulette and FATES in Ishgard/Nothern Thanalan myself :)

I found Levequests to be the best source after you've done your low level roulette and Guildhests bonuses. You can go to Mor Dhona and the Saint Coinach's camp, take all the GC leves and regulars, complete those 10 in half an hour or less, and get around 150K for each ten you do more or less.

Dzemael Darkhold first few room runs for 44-46
Arum Vale first room runs for 47+

GC levemete since they give better exp than regular leves. You can also grind Dzemael Darkhold/Aurum Vale and while you wait for the Duty Finder you can do fates in Dragonhead and Northern Thanalan, i like Dragonhead region better because there's always a fate up there.

Don't forget about your hunting log.

I found that I'd complete as far into the story quests as I could until a big jump occurred, I'd then do leves and FC fate runs with a few roulette thrown in. This had me levelling to the next story quest pretty quickly. Rinse and repeat .

Dzemael Darkhold and Aurum Vale.

The new Challenge Log and finish your Hunting Log #1. Not completing logs before 50 is a waste.
#2 take your pic FATEs in South Than and Outer LaNos -OR- Level 45 Leves and GCLeves in MorDhona
While queuing for #3 DD and AV.

Optionally, you can use Party Finder for a 1st room grind group in AV and DD. And you should do all of your guildhests on each job before 50 and do your guildhest and low level dailies every day.

45-50 goes very fast. ^_^