If you want the best Essence then you need local silver currency from one fishing daily and the local warbands to buy the essence recipes. To increase your chances you need a Westernmet Journal bought with Rohan Iron coins, again after questing is done it's Rohan warbands for the currency.
Is there another way to get the journal recipes than to go back to Rohan to kill warbands for the iron coins?
If you want the best Essence then you need local silver currency from one fishing daily and the local warbands to buy the essence recipes. To increase your chances you need a Westernmet Journal bought with Rohan Iron coins, again after questing is done it's Rohan warbands for the currency.
Is there another way to get the journal recipes than to go back to Rohan to kill warbands for the iron coins?
The other way besides grinding warbands for Journals is taking another character through West Rohan. Same for Amroth Silver tokens, although you have not mentioned the Tarlang's Crown normal daylies - not the ones you pick up in Amroth.
Shards can be bartered in the Skirmish camp, relatively cheap.
Solvent is the really rare stuff, you are usually better off buying it from the AH as other players with enough TP will buy them on the store and sell on the AH.