When you're out hunting mobs I usually would go solo. If you're decently geared and are able to kill stuff then I would stay soloing. Having an ally in group can slow things down when they afk, die or whatever the possiblities may be. You should target green or blue con mobs. Nothing too difficult because it may cause you alot of downtime. If you're a caster, preserve as much power as possible and if you're a tank preferve your health. Areas with less players and more mobs are ideal spots. Do not use any soulshots, can cost alot of money and it'll add up. However, I would suggest keeping a few around incase of danger.

Gather as many quests as you can. If you're on the road and a quest is conveniently nearby then you may as well complete it. You can gain extra experience, adena or items. I would suggest any quest that gives alot of adena or valuable items. Even quests that involves killing alot of monsters are good. It'll help you level while you are farming for adena. Avoid taking long routes to places unless they have alot of mobs for you to kill.

There are many mobs that drops good items and valuables. Some mobs have good drop rates versus others. Always try to farming the ones with good loot and adena over another that doesn't drop anything. Killing better mobs can help add to your adena fund.

Avoid buying items from NPC merchants when and if possible. Player crafters in the game usually always charge less than the average NPC. Do not always sell off everything you loot to a NPC, there are many crafters that are looking for what you may have. Your junk may be a treasure to them. Players usually always buy at rates higher than what the NPC has to offer. You may also want to setup your own store and sell off the items there. If you're the type of person that usually leaves their computer on at night when you sleep then it would be a good idea to leave the game running with a store opened. Avoid selling more than 3 items of the same time and set prices 5-10% below NPC price and you're good to go.

Arrows, healing potions and soulshots are common items that players will always buy. It's usually a good idea to carry extra of those around if you have room. While traveling players may run out of goods and will need to stock up, you can take advantage of the situation and sell them your extras.