If you’re in an unpopulated system and can’t scoop or don’t have a scoop, but aren’t out of fuel please stop and stay as close to the source star as possible.
A lot of people tend to pick a direction and start flying, but this makes the job of whoever comes to get you a lot harder, stopping near the source star means a fuel rat can get to you quickly after landing in the system.
Another good option is to log off before you’re completely out of fuel, this will additionally greatly increase your chances of survival.
I had a friend run out of fuel about 400,000ls from the source star last night because he picked a direction and didn’t stop flying. Luckily I was able to get back to my carrier and grab my fuel beluga, and head his way. We used 15 seconds of air for a relog to get a direction for me to fly. I proceeded to make a rough calculation of how long I’d need to fly in the direction to be within 15-20 seconds of his location (this turned out to be around 12 minutes including the initial acceleration into supercruise) sure enough as he relogged he was 25,000ls away (30 seconds) and I engaged the nav lock and dropped in 200m away from him. Saved his rebuy and the 10mil in bounty vouchers I’d just gotten him in a haz res.
This rescue was much harder than the one I performed for my last friend (he ran out of fuel right next to a station) but during this rescue I managed to have fuel in his tank at the 22:30 left on air timer.
Note: I am not a fuel rat, but I really respect those guys. I follow their protocols anytime I rescue one of my friends, and their work saves lives in this game. I’m lucky enough to have not needed their help yet.