Here are the two processes that form part of any divorce:
Firstly, there is the court procedure that legally terminates your marriage. This consists of compiling and filing the correct paperwork with the courts, a process which ends with a judge making a legal order that your marriage can be ended (Decree Nisi).
Secondly, there is the negotiation with your spouse about how to actually separate your lives again, in practical terms. This could include discussions about everything from how to fairly split joint savings accounts to who does the school run on a Tuesday afternoon. (This negotiation process usually ends in both parties signing up to some kind of a matrimonial agreement.)
Just because you might not have actually started the legal divorce process, does not mean that you should not think about the practical things you and your partner need to agree on to separate your lives.
(Likewise, you shouldn’t focus all of your attention negotiating the practical matters, while ignoring the legal process that you will need to complete properly get the divorce in the first place.)
If you have given thought to these issues in advance, you will be better equipped to deal with them when they arise.