An encounter with two guards at the city gate isn’t fun. Tell the players they get through the gate without much trouble and move on to the fun. Niggling details of food supplies and encumbrance usually aren’t fun, so don’t sweat them, and let the players get to the adventure and on to the fun. Long treks through endless corridors in the ancient dwarven stronghold beneath the mountains aren’t fun. Move the PCs quickly from encounter to encounter, and on to the fun!