I've updated Kovus' Fill4Me mod and made some minor improvements. If filling turrets and furnaces is as big a pain for you as it is for me, then this mod will help. You can find it here: https://mods.factorio.com/mod/fill4me-continued

Simple description: When you place a furnace or turret, it will automatically fill the fuel or ammo in that furnace/turret with something you're carrying. Configurable counts/percentages and even a fill-everything-nearby.