Lots of great answers, so no much for me to add, and I’ll probably repeat some of what was already said.
Known airports are of course the safest option, but if you stick to only known airports, you will significantly handicap yourself and will actually land out more often.
Known fields are somewhat less safe since the field condition changes through the season, but are usually good options.
Unknown but good looking fields are almost as safe if you know what to look for, especially power lines, fences, slope, surface type etc.
The last in the list are unknown fields which looks like they will probably be landable, with risk of ground loop. These could be sonsidered only when the likelihood of landout is low (chances of finding lift are very high). As a rule of thumb, the less the chances to find lift the more conservative your options should be.

In David’s case, he found himself very low over unlandable terrain (4WD dirt roads in the mountains are unlandable) with no plan B, and nearly zero chance to find lift, and had to crash land. He now owns a glider with an FES

In 20 years of aggressive XC soaring I have well over hundred landouts, but less than 10 in fields, and less than 5 in unknowns fields. The worst damage I had was a gear collapse in a rough field (in an LS4 which are notorious for gear collapse) and very recently some belly scratches due to landing in a plowed field.
Well there was that winnemucca dry lake landing which wasn’t completely dry, but this is another story for another time, and over 20 years ago so don’t count, but yeah, beware of dry lakes which may not be dry....

Ramy