We called these 'unwanted off field landings' you don't only learn to read the sky (looks like an art to you now, but it really becomes second nature to "fly out" turbulence and take advantage of it, or know where to suspect it) you learn to be on the lookout for fields suitable to land on too. The biggest risk with off fields is that you want to select a field that can be accessed by a glider trailer, where your pickup crew can get the plane without carrying it for a mile and a half through the sticks.
Your field selection is imperative (smooth, somewhat even) and just like when landing on a lake or river in a seaplane you try to find out where the wind is from by looking at bodies of water, smoke stacks flags... everything. From that point on it's treated like a NORMAL landing. You're coming short of your goal and the first step is to realize and accept that. Denial has put many planes in the weeds. Its only an emergency if you let it be one. Think: Engine = failed anyways, what else can go wrong? Big deal...
The flight to GA is just like any XC flight a plan only. You have your radio, most gliders today have GPS and fishfinders for thermals too, it appears) and you keep adjusting your plan to what you find. You liely (thats likely!) select a bunch of ideal fields in your target state and along the way, but you can never be to proud to drop it and take a step back. Preferrably (and likely) Gliderpilots in the US are just a nuts as the ones in Germany, they help each other out all the time. If someone has a towplane, you may hitch a ride back to altitude and keep plugging... Otherwise, some extremely lucky guy like me 10+ years ago, gets to take a Cessna 172XPII to an airport 200 miles away and tow this student all the way back to the homefield.
Its wonderful to do touch and goes in tow. We did that on long fields with Instructors on board, but even practiced landings in tow. It is an awesome feeling to approach a CB or nice Cumulus and experience how it sucks you up. Needle all the way up, full spoilers + steep turn, stick forward all the way and you are still climbing... (thats when you get scared and try to spin away from it!) But just experiencing the tremendous power that comes with these clouds will floor you. Endless fun, just gotta be open to it and learn from the ground up.