On top of exploration, questing and combat, you have the opportunity to hone your crafting skills as well. These are: Mining, Gold Panning, Herbalist, Fishing, Alchemy, Junk Art & Ragpicker. Using these isn't compulsory, just highly recommended. I mean, really highly recommended. :) With a little more time invested, you can get that extra edge to make yourself more effective in combat or other situations. Not to mention the material benefits you can use in shops and during questing.
There is crafting equipment scattered around the world everywhere and there are few crafting camps as well where the most serious business (ie. fetching ingots) can be carried out. It is possible that you won't be able to train every crafting skill to high levels, so focus on a few. However, you can find items and buffs that help you overcome this hindrance. In general, sidelines are very handy and you can even get a few quests too if you immerse yourself in sidelines.
Crafting will fill your inventory quickly and the products will also weigh you down. This is why you need more party members, higher strength and carrying capacity. If you can't get these, you can still contain your finds in containers all around the world. You just need to remember where you left them behind. If you don't want to "waste your time" on sidelines, take ragpicker. It'll help you find more loot in chests and on defeated enemies.