One big thing that I've always believed in is "document that which you wish to prove". The corollary of that being of course "don't document that which you don't want waved in your face". In this day and age "document" has a wide reach depending on how keen the assistant is while doing discovery.
From my own reading (I've taken some courses but am not a L) it largely boils down to "don't be an @ss". So don't block access to marital resources especially the marital home which in this area has a special status in the law. This also includes not emptying the bank account or moving assets to another party. With that said I've put alerts on all of our accounts so that I know within seconds of any transaction over a certain dollar value. I also know how to lock the funds down so it requires 2 signatures for any transaction and how to cancel her part of our joint credit card within minutes. Having strings on all of these levers makes me feel better that "she" won't do anything too damaging. I just make sure to act surprised when W mentions to me banking/spending that she has done that I knew about hours earlier. I've also changed my will putting clauses in place that invalidate any of her claims if we are separated or divorced assigning them instead to our adult children.
In my case my W is in full paranoia mode some days and even though she is quite smart I'm reasonably sure that she hasn't taken similar steps herself. You can't trust that your's hasn't done that though.
It's amazing how helpful and sympathetic people like bank managers can be when approached by a LBH with a request for a confidential bit of information.
Good luck.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells