I personally often times do NOT say "gg" unless it is rightfully earned by both players.
Getting crushed and having your opponent saying "gg" is not very satisfying.
Likewise, crushing your opponent and saying "gg" seems like salt in the already deep wound.
I played a good high rated player and caught them early in the game with a blunder (pinned Queen/King). Telling that person that it was a gg clearly wouldnt be the truth, but I did tell them that I hoped they get some better games in the future, and I did mean it. ^_^


If my opponent was a jerk, then I just click resign. If my opponent played well and was not rude about it, then I type gg and then click resign. If my opponent played exceedingly well, then I type vgg and then click resign.
It's nice to have a winning position. But instead of a resignation request you should play as strong as possible and try to force a mate.The opponent will resign as soon as he realizes that mate is unavoidable. I've lost "won" games because I was too lazy to convert the advantage into a mating attack. But I also could end games with crushing material edge quickly finding a more or less forced mate.