How to make managing pictures easier on my iPhone 5?

Every time I sync my phone it adds every picture I have on my laptop to my phone and I wind up with several locations with the same photo and photos I can't even delete. When I try to take anything off, it wants to delete all the pictures from my phone and everything. Its taking up a lot of memory.

Using iPhone
1. Turn on your iPhone and tap the "Photos" icon. Tap "Camera Roll." You should see a list of the pictures that you have taken with your iPhone camera.
2. Tap the photo that you want to delete and tap the trash bin icon on the lower right corner.
3. Tap "Delete photo" to remove the photo from your iPhone. Using iTunes
4. Connect your iPhone to the computer using the USB cable that comes with your device and launch iTunes.iTunes displays your iPhone on the left panel under "Devices."
5. Click your iPhone and click the "Photos" tab. Uncheck the "Sync photos from" check-box and click "Remove Photos."
6. Click "Apply" to remove the photos. Right-click your iPhone when you finish, and click "Eject." Disconnect your iPhone from the computer.