Mostly in the title, what are the best ways to make money in the game? I've been doing slots + grinding low level arenas, but I still feel like there's no such thing as enough money for everything. Is there something more I can be doing?

i'm fairly new yself so i might not have the best advice but the missions you can send you pets on seem to be the most common way to earn gold, theres more details in this guide 'Guide to making Gold'

i know for myself other then when i'm trying to level up pets the level 25 missions that are only an hour or two in the Umbra forest 9also the highest missons i can currently get) can get you anywhere from 1-5,000 gold per bag or items that can be sold for 500 gold and up if you don't need them so they're pretty useful

Also see the guide to mission pets and missions- missions are an excellent way to make gold, especially once you have all mission slots unlocked and access to all tiers of missions.
(For an overview of what the different tiers of missions can get you payout-wise, we have an (incomplete) listing of the non-mission satchel rewards here (incomplete since when I was doing it I was already capped on AP, and on reputation, and didn't really get many submissions of Fail or Poor or even Satisfactory completions from anyone) and a spreadsheet of mission satchel payouts where the averages and percentages are calculated) (pinging Lizard in case these might be interesting/useful to see)


You can also do esior farming (pick an area in viridian meadows, just run through opening up every chest you encounter), which it sounds like you might already be doing

Once you reach the Lost Grove (lv60+ area you can unlock after the currently available main plot) chests there can drop a respectable amount (on very rare occasions, over 100K in one chest! usually a few k though, sometimes somewhere between) and the equips also site-sell for a good amount.

When fests are on, doing runs of the fest zone collecting all the chests every hour or two can get you a good amount, though there won't be another seasonal fest for a while

I believe patriotic fest is coming up; in previous years you got points for releasing pets over than 42 days, likely to hold true this year. The sales floor will rise dramatically for the period of the event since people will be snapping up every cheaper pet 42+ days old for release.