1, 2 , 3 , 4, etc of speaker mod / upgrade

I have a great pair of speakers - 20 years old - top of the line, I want to upgrade. Someone told me to upgrade them in steps rather than an all out upgrade and assess after each step the improvement. I guess, sometimes it does not work out and you have to go back. Which are the steps in order. These are my thoughts
1. Binding posts - Brand recommendation?
2. Internal wiring - Brand recommendation?
3. Speaker cloth over drivers - Brand recommendation?
4. Crossover capacitors - Brand recommendation?
5. Crossover coils - Brand recommendation?
Thanks in advance for responding