Grab some OE fists, nuke undead mobs and wack the last hp.
Get a nuker friend and duo.
Find a cataparty -> buff an heal.
Get some OE fighter weapon, duo with some DamageDealer.
I have mine in Manticore set [light armor +92 mp] and a good weapon. I had dragon fang which was good, but got a better hand-me-down ELS. I also use a hatchling sometimes -- wind are great fighters. I have her hit first always to protect him, but then he can take down one when another monster attacks if she switches quickly. Been doing pretty well in the wastelands. Just avoid the 3-some ants Gigantro....? Death pass is also good; not too aggro, and if you are high enough to manage the fettered souls, its pretty hefty exp.
PS: I keep up MP by using spell for first strike [windstrike or vamp touch] then going in for weapon battle. Some of the wasteland mobs are magic resistant, so the sword or blunt weapon is a plus. If my hp takes a hit, I use Vamp Touch the next tiime instead of wasting mp healing.
When I lvled my SO, I already had some money made with my BH, so I was just able to afford a mithril tunic and stocking and Bastard*Elven (I got gloves later on) I wasn't that fond of parties at the time as I was rather shy and unsure about myself. till ~30 I soloed monster eyes at the hills of Dion 1 windtrike for starters and duals did the rest. after that I rather enjoyed my Disturb Undead(I think its called? havent used it in a year) skill in execution grounds, just nuke first and hit the last bit if any hp remains.
The last part (lvl 37+) I got cata parties :)