My fraternal twin girls are now 12 years old and yes, I agree--treat them as two siblings who happen to be the same age. They are very different. I kept them together in kindergarten as I thought that they would make the transition from pre-school better that way. Then they asked to be separate classes. For Middle School, they wanted to be as far apart as possible which worked out great. The less they see each at school, the better they get along at home. They either love each other and play well together or fight like crazy--just like different aged siblings.
Do what you have to do to make your life work. I also found that a schedule was essential partially because I needed breaks. You're always on with two. When going places, I kept my daughters in their double stroller longer because it was lot easier than walking sideways to keep track of my fast walker and my dawdler.
I let them pick out their own clothes as soon as they could. Except that on the advice of a friend with twin brothers, I would dress them alike in public to keep better track of them when they were young. I didn't have to think about what they were wearing. Once I was holding one girl and frantically looking around for the other, another mother just pointed in the direction that my quick moving daughter had gone. Twins do have more accidents than singletons so be prepared when taking toddlers out. I loved my minivan with the "magic" door. I didn't have to let one little hand go to open a door; just used that remote door opener.
Don't worry about how parenting should be with twins. All kids are different and if you love them, and respond to their needs, they'll be fine.