whether you do the original athena quests or the haven runs leave all non athena loot
this significantly speeds things up
you'll be tempted to take the loot you're a pirate after all but it's not worth the time transporting it and it keeps you in danger longer. Gold is easy to come by. Athena voyages are for the rep not for the gold there are way better ways for gold.
take down every prespawned skelly sloop and meg you see
captain riddles help with rep do the quick clues
Don't spend any extra time on land get in get out with only the athena loot and move quickly to the next spot. Athena runners are always at risk.
Haven is better for loot but easier for pirates to hunt and disrupt (especially a solo) an original athena gives you more options when you need them.
I'm maxed on athena but I still run them to keep on the top tier of the emissary ledger. I do the original athena and take a couple tries on the voyage table to get a route i want and islands i want
riddles/cargo don't matter as much I want my dig islands to be as easy as possible and my skellies to be on small islands for 2 reasons they are easy to find and easy to cannon
a good route mixed with good islands for dig/skelly and only picking up athena items is the way to go imo
both athena voyages you have a chance to dig up athena kegs but the haven voyage you have a chance to dig up a legends chest I've found a few on haven voyages
sell on a regular basis. It's better to cash in items at grade 2 or 3 then to lose all your loot thanks to a series of unfortunate events while waiting to hit 4 or 5