I don't really have any specific tips but I can say that I moved from a Droid Razr to my S4 about two months ago and haven't looked back. Feel free to add as many widgets and homescreens as you need to your S4. I have six pages full of widgets (overboard? heck yes!) which I could never have done on my Razr. It would lag like crazy with a minimal amount of widgets, but I haven't even had so much as a hiccup on my new phone.
Another cool feature is the infrared sensor on the top of the phone. You can use it to control your TV, cable, and entertainment center plus there is some apps out there that utilize it that can be some fun.
I also continuously had problems using Google Now on the razr, which we all patiently waited for release in Android 4.1. No worries with the S4, it's glorious.
I really enjoyed the Droid for the 2 years I had it but overall, the S4 is just a much more powerful device and all the systems/apps work together flawlessly.