Daredevil
1. Less wire-fu and CGI. I realize that kind of thing was popular at the time, but Daredevil doesn't need to seem like Spider-Man 2.0. The action sequences should still have a Hong Kong martial arts vibe, but with a grittier and street-level vibe most of the DD fights didn't have.
2. Elektra and Matt should have a past prior to the coffee shop scene, where they should reunite instead of meet for the first time. Besides being truer to the comics, it would more effectively set them up as kindred spirits.
3. Elektra returns in the present day as an assassin working for the Kingpin. She's hired to kill Daredevil, but when she learns he's Matt, she instead tries to enlist his help in her covert mission to bring down the Kingpin, whom she suspects was responsible for her father's death. Matt reluctantly goes along with the plan, if only so he can keep an eye on her and prevent her from going past the point of no return. Of course, Elektra sees his refusal to let her kill Fisk as a betrayal on Matt's part.
4. No Bullseye, for a variety of reasons. While he's a great villain, he should be shelved until a sequel, where he can be brought in as a solution to the problem of Daredevil and Elektra. Which brings me to:
5. Elektra isn't killed off until the sequel. The reason her death in the comics was so gut-wrenching and powerful was that she had been a regular character in the comics for several issues. Readers were able to care about her just as Matt did, because readers were able to spend time with her. She had very little space to show up and grow as a character before dying in the first movie. Instead, the first movie should be about Matt and Elektra's reunion, and Daredevil trying and failing to save her from what she's become. In the end, he prevents her from killing Fisk, but at the expense of the final bridge being burned between Matt and Elektra. In the end, Matt wonders if the Kingpin was even worth saving in the first, and if the Elektra he'd known had already 'died' long ago.
Maybe if that'd happened, we could have ended up with a Daredevil 2. I would even have been fine with an Elektra movie, showing how she bides her time until her return in DD2. So with that in mind:
Elektra
1. Let's go with an entirely different story. The Hand-vs.-Chaste element is still there, but without the stuff about Abby and her father. But keep Terrance Stamp as Stick. He was awesome.
2. Elektra is shown rejoining the Hand, rededicating her allegiance to it after the events of "Daredevil". She believes she's exices all remaining traces of her humanity and compassion, and the Hand test that theory by having her assassinate Stick and the Hand.
3. They're all wrong. Elektra's attack on Stick is thwarted, and she essentually becomes his live-in captive/pupil/indentured servant. Or in Elektra's eyes, "slave" might be a better word. But he gets her to see that maybe there's still a spark of humanity left in her. This finally gets through to her when she's able to kill him, and he doesn't resist; she feels conflicted and remorseful about it afterward.
4. Let's not have Hand members who're basically mutants from the X-Men franchise with Hand names. Kirigi should be a silent and all-but unstoppable killer of all who oppose or have failed the Hand. This would be proven when Elektra returns to them to report that Stick is dead. The Hand's elders believe that Stick's influence has 'tainted' her, and that she cannot be allowed to remain alive, much less a member of their clan.
5. Actually EXPLAIN the Hand's habit of dissolving into smoke upon death. The comics revealed that it's a chemical reaction to a toxin they voluntarily enter into their bloodstreams when they die, and that explanation would go a long way toward keeping these ninjas from getting confused with vampires. After Kirigi goes up in smoke, Elektra manages to fight her way out of the Hand's compound, she finds that Stick had faked his death. He explains that the 'taint' in her soul that turned the Hand against her wasn't simply due to his influence; it had existed in her all along. He knew that it would take his murder at her hands for her to see what she had become, and the Hand's reaction would show her that it wasn't what she wanted to be. While she feels manipulated, Elektra still heads for New York, pondering a possibility that she might be able to reconcile with Matt.
Hopefully this approach might lead to a Daredevil 2, in which Elektra actually makes an honest attempt to have a normal life with Matt. But yeah, that doesn't go as well as they'd like, what with that jerk Bullseye being Kingpin's new assassin. Bullseye makes Daredevil's life hell, Kingpin makes Matt's life hell, Elektra takes violent exception to all this, and sooner or later it leads to the Stabbity Heard 'Round the World. Good times.