Techniques can be literary and Dramatic. Quote would be ideal too to back them up.
I've always thought the final scene between Laertes and Hamlet has an interesting moral dynamic. The two men are battling to the death but for different reasons--Laertes to avenge his father's death and Hamlet, I think, because he feels his fate closing in around him (as evidenced by his conversation with Horatio prior to the dueling contest). Despite the harms done by each of them to the other, each of them asks for and receives forgiveness before dying.
The other moral issue of the play is the marriage of Claudius and Gertrude. Hamlet is repulsed by the marriage; the ghost calls it incestuous; and even Gertrude acknowledges that it was "o're hasty." Denmark is a Catholic country, and this marriage would have had the tinge of incest in eyes of the church. Even Claudius appreciates that this marriage is unconventional as evidenced in his first monologue when he thanks his court for "going with this affair along." Claudius needs the support and approval of courtiers such as Polonius, but we must remember that courtiers serve at the whim of the king, and benefit from being in his favor, so their support has be considered in light of what they gain for it.
Hamlet is absolutely appalled by the marriage. He stews about it for three acts and when he finally has the proof he needs to deal with Claudius, he instead lets himself be side-tracked into a conversation with his mother where he spends several pages trying to convince that this marriage is wrong and he advises her on the necessity of getting out of this relationship with Claudius. It is interesting that the "closet scene" is by far the longest scene in the play and deals at length with the Gertrude's morality and Hamlet's judgement of it.
Hamlet deals with the concept of revenge, a pagan act that goes against the Christian morality of Prince Hamlet. But, Hamlet is ordered to kill Claudius by his father's ghost (who is stuck in Purgatory):
This presents a profound moral dilemma for the prince. If Hamlet kills Claudius, Hamlet himself may well go to hell. If Hamlet refuse to kill Hamlet, his father may go to hell. So, Hamlet must morally find a way to kill Claudius without sending either his father or himself to hell:
Hamlet's plan is to put pressure on Claudius to confess his sins publicly. This is why Hamlet stages the "Murder of Gonzago," and Claudius certainly takes the bait: he confesses, but in private. Hamlet refuses to kill Claudius during prayer, since he believes he will send his soul to heaven:
Now might I do it pat, now he is praying;
And now I'll do't. And so he goes to heaven;
And so am I revenged. That would be scann'd:
A villain kills my father; and for that,
I, his sole son, do this same villain send
In the end, Hamlet achieves his moral goal: he exposes Claudius' guilt publicly (the King poisons Gertrude) and sends his soul to hell. Hamlet dies in the process (a murder-victim), presumably going to heaven.