Here's a mini-discussion of the two logging options I use for POTA activations. Link to the original Reddit thread here.
HAMRS is absolutely fantastic for POTA hunting.
One of K8MRD's YouTube videos turned me on to it. With an internet connection (not hard to setup a hotspot with a smart phone as long as you have cell service), you can copy details from any POTA spot (callsign, park, frequency, etc.) directly into your QSO record. Then you only have to enter both signal reports and you're done. If it's a 2fer or 3fer, you can either repeat the process with other spots or just add the extra park or parks to the park field, and the app will save individual QSO's for all parks involved.
As a backup, I nearly always export my logbooks to an ADI file as soon as I'm done activating, save them to my hard drive, and email them to myself before I pack up. If you're planning a really long activation, you can always make a habit of exporting a backup every 10 or 20 QSO's to be really safe.
When logging non-park to park contacts for an activation, HAMRS will pull in any data from your designated database (QRZ, HamDB, and HamQTH are all supported, but internet is required). Once you get the hang of it, you can just enter the callsign and signal reports then lookup the grid squares after the fact if you wanna include them.
For the truly lazy ham such as myself, the simplest thing to do is run a digital mode for your activation. It is easier, of course, on some rigs than others to setup digital modes, but once that's done, the software will do nearly all of the logging for you. WSJT-X can be configured to prompt for confirmation with every completed contact. For example, sometimes on FT8, I have to enter a grid square manually-- especially common when the QSO is interrupted and I have to pick it back up later. Honestly, it's like having a little radio butler with you. I've added GridTracker to the mix for my last two activations, and it's like the radio world is a menu at a restaurant where I'm the richest guy in town.
With these tools at my disposal, my default MO for any activation is first to hunt all SSB spots I can get for Park 2 Parks, logging those with HAMRS. Then I switch over to FT8 to get as many contacts as I can that way. Finally, I finish up by trying to hunt some juicy DX contacts with admittedly mixed results. But that's my 10 watts through a ground mounted vertical antenna with only 3 radials talking there-- nothing to do with the logging strategy. Managed to pull off a Park 2 Park QSO with a ham in France on FT8, so it can be quite rewarding.