You basically have them in order...
Start with Ten Miles of Peach Blossoms. because it introduces all the characters.
Once Upon a Time is just a condensed version of the drama and it omits a ton of info so if you want an idea of what the series is about then start with this.
The After Story- never watched because the reviews were bad.
Love and Destiny- haven't watched it yet but will soon.
Eternal Love of Dream- gives backstory to a very popular side couple that were in Ten Miles so watch it afterwards
So my watch order is: Ten Miles, Once Upon a Time, Eternal Love of Dream, then I'll be watching Love and Destiny soon.