Fate of the prisoner
In Ostagar you discover a starving deserter, locked in cage. How you deal with him is an early barometer of your Warden's personality - ruthless, cruel, pragmatic, diplomatic, or simply willing to spend money to solve problems.
Did you help the dog?
If not, why not? There's a sick Mabari hound in camp, and you can either ignore him or find herbs to cure him. The latter is how non-noble Wardens come to acquire a dog of their own; it's also the right thing to do, you monster.
The Arl of Redcliffe
Depending on your decision to take an active hand in the quests in the village, you either helped the villagers to fight (or not) and helped them to prepare (or not). This is a rather neutral decision, in terms of what it says about your Warden - unless you're roleplaying as an absentee protector, in which case go for 'not'.
You're sent to find a missing child, Bevin, who is discovered cowering in a cupboard. Your options determine whether your Warden was intimidating or compassionate, and how they go about acquiring Bevin's family sword (or not) determines their honour. Paying for it or returning it later are the signs of a trustworthy warden; promising to return it and keeping it signifies a douchebag.
She's found in Redcliffe Castle itself in the final part of this questline. Discovering her counts as rescuing her with few other choices of lasting significance to make. Another 'did you do this?' option.
Bella and the tavern
The fate of the tavern waitress, Bella, dependings on how you interact with both her and her boss. If you bully her boss into fighting for the village, he may die - in which case she takes ownership of the tavern. If the Warden is generous, she can be given money to leave and found her own business. Alternatively, she can be persuaded to leave or abandoned to die.
The Arl's wife, Isolde, will offer to sacrifice her life if the Warden chooses to use blood magic to enter the Fade and kill the demon possessing her son, Connor. The only way to avoid this is if the Warden went to the Circle of Magi first and resolved the quest line there in favour of the mages, in which case they'll be given the option to use lyrium instead. A diligent and compassionate Warden may take this option, while a less scrupulous (or rushed) Warden may end up taking Isolde's life instead.
What the Warden then does inside the Fade determines Connor's fate. He can be killed, if the Warden does not act, or the demon can be slain, sparing him from possession. Alternatively, a power-hungry Warden may make a deal to free the demon to return later.
The Urn of Sacred Ashes
While seeking a cure for Arl Eamon, the Warden is given the choice to defile this sacred relic in order to gain tremendous personal power. Doing so has ramifications for Wynne and Leliana, as detailed above. In short: a good Warden will likely leave the Urn alone, while a bad Warden will get all up in them ashes (or whatever defiling ashes actually entails.)
Nature of the Beast
The Warden encounters a Dalish clan (which may be their own) in conflict with werewolves. It turns out that the clan's leader is responsible for the curse, humanising (possibly literally) the monsters the Warden has been facing. You have the option of recruiting the elves or the werewolves separately, or brokering peace by breaking the curse and bringing the Keeper to justice. If you're roleplaying a Warden with a strong elf- or human-centric mindset you might pick a side, otherwise it's inkeeping with the Warden's role as an investigator and diplomat to go for an alliance.
Cammen and Gheyna
The Warden may choose to help these two elves find love with each other. Alternatively, it's possible to seduce either one of them and ruin their relationship. This is another decision to make based on your internal sense of how much of a prick your Warden is.
There's a sick deer-like creature in the Dalish camp. You can heal it, which involves a bit of extra legwork - therefore the preserve of diligent wardens - or put it out of its misery. Or you can ignore it. Who are you, captain-doesn't-do-things?
You're sent after this cursed elf by her husband, but you discover a werewolf. You can follow her wishes and execute her, or be forced to fight her for spending too long asking questions about her condition (the curse of BioWare protagonists everywhere). Alternatively you can ignore her, in which case her husband will seek her out if the werewolves are later cured.
Varathorn and ironbark
He's an elven craftsman with a thing for really hard magical wood. You find a piece of really hard magical wood. What do you do? Really, it's about ethics.
You're asked to find a lost elven scout in the forest. Unless you're roleplaying as a Warden in a hurry, you probably found him. If you found him, you either killed him for his shoes or returned him to his people. Another 'are you a dick?' moment.
Next page: Orzammar, the Circle, and Denerim