Right to introduce Farming + Herb to the game I would first add a caterby tele, now next of all you should find a location for Druids.
Once added they should already drop seeds, now once they are added all you gotta do is go to catherby fruit tree farm patch (ill screeny it in a sec) Use the seeds on them and u get herbs. use the herbs on vials and you get your pots.
My next suggestion would be add jellies somewhere (they drop Horror From The Deep books) and require 30 slayer to kill.
Add the dag kings, as they drop rune cbows used later for fight caves.
Thats all for now