General

@Masterobert: How much money did it take you? I'm planning to do this as well and got the info from a guildie.

Buy/Make a massive amount of Opals (I believe its around 5,700 or something)
Make arrows.
Once you hit level 10 smithing, unlearn it.
Relearn it.
Repeat.

When you're completely fatigued, buy the 100,000 meso fatigue reducer. You'll need something like 777 to max diligence.
I think when I started maxing diligence I had 360m mesos. After I had something like 245m. Plan on spending about that much. I already had about 2,000 opals before I started and it still cost that much it's completely worth it though. Landed all 7 slots on my earrings with only 17 10% earring for INT scrolls.

@higuy1213: It's not going to take 400m...
@Convasive: The extra success rate from diligence does NOT work on:

[quote=Masterobert]
Epic Potential Scroll
Potential Scroll
Advanced Potential Scroll
Equipment Enhancement
Advanced Equipment Enhancement
Legendary Black Dragon Chaos Scroll
Chaos Scroll
Miraculous Chaos Scroll
Positive Chaos Scroll
Clean Slate Scroll 1%
Clean Slate Scroll 3%
Clean Slate Scroll 5%
Clean Slate Scroll 10%
Clean Slate Scroll 20%
Cursed Clean Slate Scroll 1%
Cursed Clean Slate Scroll 3%
Cursed Clean Slate Scroll 5%
Innocence Scroll 20%
Innocence Scroll 60%
Innocence Scroll 70%
All 50% Scrolls[/quote]

@fmonglobal
No. Reaching levels of Smithing bypasses the cap.
Educate yourself before trying to tell me I'm wrong, when i'm just helping someone.

[quote=fmonglobal]No. You can only each a max of 500 of each trait each day. It will still take a few weeks at least to max Diligence.[/quote]
That is not the only way to max diligence, although it is the cheapest. If you gain a level of smithing, you gain diligence exp regardless of whether you've gotten the daily exp or not.

[quote=fmonglobal]No. You can only each a max of 500 of each trait each day. It will still take a few weeks at least to max Diligence.[/quote]
The diligence received from leveling up smithing bypasses the 500 EXP/day restriction.

[quote=higuy1213]@Sparksy 's method is the best and fastest. If you decide to use this method, it will take you about 400m and 5 hours.[/quote]

No. You can only each a max of 500 of each trait each day. It will still take a few weeks at least to max Diligence.

My friend gives me free oils so I just make potions. 500 EXP diligence each day isn't that bad.

Oh yes, along with Sparksy's method I hit it fairly fast lol

@Sparksy 's method is the best and fastest. If you decide to use this method, it will take you about 400m and 5 hours.

I hit Level 100 diligence by doing monster park for mustaches, zak solo for helms, dojo for belts and aqua road for charm.

okay sweet! thanks a whole lot!

Mass craft stuff in Ardentmill. I think the best option would be to craft arrows non-stop till you hit 100 diligence. Keep in mind that once you hit 10 smithing, you have to relearn it in order to get the diligence(from leveling up your smithing)

Edit: Guy above me has it more simplified.

Make opals
Make arrows
Reach lvl 10 smithing
Reset
Repeat

Go to Evo World, Put in x mineral / herb drop with the +50% drop rate on mineral / Herb with a +30% extra drop rate core and a giant spider?