It's certainly harder than it used to be. Keeping low numbers of troops, levelling them up, picking your fights carefully and keeping aware of enemies while you're travelling is pretty important I think. Trading can work, as you say though it's a bit hit-and-miss where you go to "talk to traders" as to the possibilities. And it takes a long time irl. Enterprises are good, but take a LOT to set up in VC, so the pay-off is a ways down the track. Raiding can be lucrative, but makes everyone hate ya....so can be harder down the track, too.
What I've found that works fairly well beyond the occasional trading and obvious bandit fights: Tournaments. If you bet maximum each time and win, it's a decent payout and also you can sometimes get good gear. Also good for relations with towns. My current game char has nice mail and made lots of money that way. You've gotta win though, which, like trading, can be very hit-and-miss depending on agro. Always get your team to follow you instead of running off in separate directions to get beat down...