Short little thing for ya.
Things You Need:
5 herb seeds
5 supercompost
Spade
Dibber
(Magic) Secateurs
Ectophial
Skills Necklace (Ardougne cloak if you haven't used the teleport)
Camelot teleport runes (optional)
Explorer Ring 3
Falador Shield 2 (optional)
Trollheim teleport runes
Port Phasmatys
Teleport: Ectophial
Run West to farming patch. Pick & plant.
Falador
Teleport: Explorer Ring 3
Run North to farming patch. Pick & plant.
Equip Falador shield for more exp.
Ardougne
Teleport: Skills necklace to Fishing Guild (Ardougne cloak to farming patch)
Run East to farming patch. Pick & plant.
Catherby
(Teleport: Camelot)
Run Northeast from Ardougne patch OR run east from Camelot. Pick & plant.
Trollheim (Requires My Arm's Big Adventure quest completed)
Teleport: Trollheim
Run down the hill, through the trolls and up the ladder. Pick & plant.
As for what type, I do irits/cadantine/avantoe, 'cause the seconds are easy to grab (eye of newts, whiteberries, mort myre fungus) but if you buy the seconds, then I don't know. xD