A few tips

Having racked up over 300 hours on my recent playthrough, ive found some little tips i thought some people might find helpful.

Entite chaining.
All the entites can be chained using the same chain level, helping to find those halycons a little easier. I like to start in the Giza plains during the wet season with the Mardu entite, then move two zones into the westersand for an almost garanteed sandstorm to chain the Gnoma entite. Then move into the Ogir yensa sandsea for the salamand entite. Next run through the zertinan caverns and come out in the ozmone plain to chain the sylphi entite there. From here move to the entrance of the Golmore jungle and use the strahl to go to the Phon coast, where you'll have to walk through the Salika wood to reach the nabreus deadlands so you can chain the Leamonde entite. After trekking back to the strahl, head for the Cerobi step to make quick work of the entite there, then strahl to the Paramina rift to chain the Leshasch entite and finally trek through the feywood and into the City of Giruvegan to chain the Diakon Entite. All while maintaining your chain. At maximum chain level an entite has a 12% chance of dropping their halcyon and with theif cuffs a further 6% to steal.

Gil
Best place i find for Gil farming is one i never see mentioned. The Mum Bombs in the Great crystal have a 12% chance of dropping Diamond Armlets at maximum chain level. Each armlet is worth 10,000 Gil and with the bombs being incredabley easy to chain, you can easily rack up 99 and sell them off for a quick million. The Gargoyl barons and Ose also have great drops, worth 5000-6000 Gil a piece so if you're prepared to chain them too you can easily hit 2million in one trip.

Forgive me if their are typo's, i'm on my lunch break and may have typed too quickly. Got to get back now so if i think of anything else people may find helpful, i'll come back and add them later.