In what order should I hack / power up an unclaimed portal?

I've recently found some un-trafficked areas with unclaimed portals, and was able to capture them at my leisure. However it occurred to me while I was doing so that I didn't know in what order to go about capturing them to best advantage. Because they were off the beaten track, I was particularly concerned about receiving keys while I was there.

Baring considerations such as time and disturbances from the other faction, would it be more advantages four me to have:

• Hack the portal a couple times first, then claim it by placing resonators.
• Claim the portal with at least one resonator, hack it, and go back and forth.
• Claim the portal and fully power it up before hacking the first time.
• Claim all the portals in the area, fully power them up and establish any possible links before hacking the first time.

When initially claiming a portal, are there any strategies to have a better chance of walking away with keys when you're done?

XM charge, portal level and nearby targets will determine whether to try hacking a portal before taking it down. Is it a high level portal that will zap you for lots of XM, and you might run out of XM before destroying it or have other targets to attend to? In this case, don't hack while unfriendly.

Otherwise, esp. for portals that need a lot of repositioning and you will take almost 5 mins to kill them, always hack before attacking. Followed by another hack after all deployments are done. Never hack when its neutral or has just 1 resonator, unless you're fond of L1 items ;)

Why would you claim all portals before hacking one? You get 4 hacks, one every 5 mins. It is better to work on burning out portals you captured earlier while you attack remaining targets, unless you plan to do 20+ mins of hacking at the end.

When initially claiming a portal, are there any strategies to have a better chance of walking away with keys when you're done?

See Is there a way to increase the odds of getting a portal key?

In the case of acquiring portals, remember that attacking a higher level portal before you capture it might give higher level items, but overall less chance of any items. Thus, I expect that for keys its better to hack after it is captured, if you have to choose between the two.

You should build up the portal as far as possible before hacking except in the case of existing high level portals. Whether the portal has links or not doesn't matter.

My personal strategy is to hack the enemy portal once if it has a higher level than I can place resonators for. For instance, if I'm Level 5, I can only build the portal to L4, so I would hack a L5 portal before attacking.

Remember that a portal only yields items at the lower of¹ {your player level} and {the portal's current level}. There's some randomization, but that happens after this calculation.

1 _{Disputed fact, citation or correction needed}