Something I have done in BFA as a returning player was level my toons to 100 so that I can get my garrisons mining and herbalism buildings maxed and then with the help of heirlooms bonus, mine and herb those nodes daily and this has gotten my 5 shamans to level 105 without moving out of the garrison and not a lot of effort.
I have been delaying questing in Legion as I have been working on getting flying in the Broken Isles which has been a slow slog