Tactition mode basics:
Warrior and/or Ranger for damage
Crafting
CC* as much as possible
Don't neglect initiative
If you can handle that, then you can play around with combining builds as much as you want. As long as you can still equip your crafted weapons the rest of the stats are free game. 5 crafting and blacksmithing are a must, but with gear, traits and talents you can get that with only 1 crafting and 2 blacksmithing.
The main use for crafting is making and enhancing your weapons. Crafted weapons do a lot more damage than found ones (with some type exceptions), so it's pretty essential for making a strong character. It's also needed for enhancing your armor (resistances) and making special arrows for the Ranger. I could go into more detail but I think you want to learn it on your own. I will say that I think crossbow crafting is bugged (bad) so stick to bows.
That initiative part is something I found out the hard way. I used to figure "whats it matter when you get the same number of turns/actions either way?", but getting the first turn lets you CC your enemies before they have a chance to CC you. It often means the difference between dying before you get a turn and never letting the enemies attack you at all.
*Crowd Control, especially referring to Stun, Knockdown, Petrify, Freeze, and Charm
