Basically common mistakes I see often in solo queue are:
a) not taking objectives after teamfights
b) not warding and lack of map awareness in general
c) not knowing how to respond to the enemy team being ahead
It's not that hard to solve all three, just:
a) let their support surviving support run away and take a tower/dragon/baron/raid their jungle after a teamfight. If you so want their blood you can dive them when you're all grouped up again. No point chasing someone through the map when you could be winning the game.
b) obviously ward and pay attention to other lanes and jungler movement and spawn/abilities timers. If your top laner has his Baron warded and you get ganked you shouldn't whine about Y U NO CALL MIAASSS!!11!, you should've probably seen it coming.
c) gang up on the guy who's fed, choose your fights, use your towers as cover, camp them in brushes, ward everything so they can't get farther ahead, don't overextend, bait them to waste their ults in bad engages, pink ward dragon and sneakily close the gap, etc. If you're 1-10, you're down but you're not out, communicate with the team and just play smart.
Having said that, I sure wish people were just a little better to offset for the amount of work you have to put in to make up for them