Missions & Complexes

Missions are stable, safe income. To squeeze the last ISK out of them, however, requires some careful observation of the market and using the LP store accordingly.

Highsec exploration would be another source of ISK, but it's random.

L4 income doesn't "suck" per se. I made my first few billion running them. It does kind of push you in to a medium-term reinvestment cycle where a chunk of your income is always being spent improving your mission ship(s) though.

As already said, to maximize mission income you need to play the market to cash out of the LP store efficiently as well. Depending on your general inclinations, this can either be kind of interesting or a royal pain in the ass. It doesn't add any hours to the isk/hr ratio though; you should be able to do all of your critical market activities while blatting rats.

High sec static complexes are *usually* camped, which makes them pretty awful. Granted, you can always get lucky and blah blah blah. If you're going to go for exploration though you're going to want to use probes -- and honestly you'll probably want to get out of high sec. It's not a reliable income stream, but it can jackpot. Just don't cry to the forums when you get nothing for an hour of shooting red crosses.

Beyond that, PI is rumored to be decentish, though you have to do it in w-space or null to be truly profitable. Faction warfare appears to have been boosted a bit lately, but we won't know the income potential until all the changes are through. Wormholes are still good income but they definitely require some commitment.

So it kind of comes down to what you want to do and how much effort you want to put in.

You can make some good isk doing high sec exploration, just need to do it in areas with low population count due to lot's of competition.

To keep isk coming in, don't bypass Mag sites. Those can be quickly completed and will net you on average about 1 to 2 mill.
Radar sites are the best isk v time ratio. Those can net you up to 25 mill.
The 'unknown' Cosmic Signature combat sites (Hideout, Lookout, Watch, Vigil) can be a big payday but it's random. Expeditions from them usually will net you some Faction / Deadspace loot. Can spawn both Overseer and Commander NPC's.
The DED sites probably have the best chance to drop Faction / Deadspace loot but remember it's all random. Will spawn Overseer NPC.

Most of the sites are listed in the Evelopedia so you can get a good idea of what to expect.

I also complete the small Cosmic Anomaly - Hideaway and Burrow - since they can be completed quickly and have a random chance to spawn Commander NPC's. Some sites have a small chance to give expedition.

Lastly are the 'Landmark' beacons that show in the overview. Those are mini combat sites with about 1/2 dozen NPC's. Sometimes they will also spawn Commander NPC's.

You can try Incursions..................