Are you talkin about changin the ship's design or changin the movie?

If it's the ship's design,--I'd only change the davits and give Titanic the big ones, like her sister Britannic. And put a "cap" on top of the watertight compartments and really make them watertight.

Otherwise, I'd leave the ship as is.

If it's the movie you're talkin about,--I'd make Ruth nicer and not so greedy. Let the truth be known, Ruth wanted Rose to marry a rich man (Cal), so she wouldn't be dumped into some nursing home. When Rose marries Cal, Ruth would've been " on easy street", and well cared for. No, Ruth was too much of a greedy "stiff" for me.

I would have given Titanic more life boats. More lives would have been saved. I also would have encouraged crew members to put more passenger on board and that goes for the men passengers to.

I would have had the Board of Trade Regulations changed before hand, which would have required more lifeboats (Also I would have had special davits capable of launching them efficiently) on Titanic. Of course this isn't exactly a direct change to the ship, but because of the regulation change, it would lead to one. Also I would have had the bulkheads extended up a little more, and had them capped off. (The bulkheads were extended on Olympic after the disaster, and the Britannic when she was constructed.) Also, I would have had the double bottom hull extended up the side of the ship, which was also done on Olympic and Britannic after the disaster. So basically I would just have things done to Titanic that were installed anyway on her sister ships after she sank.

I would install radar, sonar and laser guided missiles

Considering the last collapsibles were floated off as water was comin' onto the Boat Deck, I'd say they had just 'bout enough time to launch the boats they had. Perhaps more boats wouldn't've made all that much difference.

That of course is a good point, but if there had been more lifeboats on Titanic, there's a good chance that many could have been floated off the ship as it sank, and passengers could have climbed into them. This isn't a practical solution, but one that should be considered, since 30 men climbed onboard a overturned collapsible boat floating in the water and balanced themselves to keep the air from escaping from under it. They were later rescued by another lifeboat.

I would not change anything at all. I agree with Jessica. It's hard to put yourself in that time, and change something because we know the outcome.
For their time it was not only considered luxurious, but also safe. Personally, I love Andrews's design and I probably could not have made it any safer, considering I know nothing about shipbuilding.
And I have read the same thing about the binoculars. When they were doing the trial test, they used them. But the author then said the binoculars were locked in a locker and then either the person did not make it back onto the ship, or the key was lost. A simple mistake...it could have happened to anyone. These people were only human...So I don't think it's fair for us to criticize them. I don't know if I could handle it as well as they did.