The first time thru the game I did everything underleveled and with low stats...but, I'm more in character building so I usually now get my stats up around 60+ (with exception to Honor, which is almost best left at base value) and get my 2nd tier classes. If a 2nd tier class can only be obtained east of Fargrove in the Skulldoon lands...I head to Skulldoon and rip on 50- 100 Minotaurs in the Arena. Also, you could head up to the Northern Steppes to fight Iceworms (~18k EXP, a piece) or those big beast mammoths that look like mutated overgrown bears (~18k EXP, a piece).
The two Rogue 2nd tier classes and the Budoka 2nd tier class can only be obtained west of Fargrove. So you have to do them before Fargrove closes itself from you (which Fargrove closes itself down if you go to the Venturean Forest or if you go to Lost Lake). Beat up on Minotaurs on Easy Mode with the Steal skill active for your Rogue...as you might run out of money if the Minotaur doesn't carry that huge Maul with him (worth +2000 gold pieces) when you fight him. That big Maul nets you some cash, from losing 500gp per fight with him.
I now fight the Trials and Ulm when I'm good and ready. Usually they are easy to finish when your above level 15. It really helps to boost Agility and Dexterity stats if you are not a heavy Mage user. As I love the clinging noises as enemies surround my character and have a harder time making contact. (They still hit me, but at least its not everytime).
P.S.:I hope you picked the option not to convict (accuse) House of Fathien of taking the Argalyia when you did the Trials...because if you did and don't have a save file from when you chose that option...you won't get the "Noble Herald" (+2 Strike, +2 Parry, +10%damage). {That was a stupid function in this game...as I was under the impression that there were no wrong answers in this game. I guess it really is a roleplaying game...where decisions count...who'd a thunk that?}
-Planet_Guardian