....what would you do?

My wife and I are still together, but I can't see it lasting. I need to start preparing myself.

If you could go back in time and give 'you' from a few months before you split some advice, what would the advice be?

Example: I'm making a bit of extra money at work at the moment, which I have been using to overpay the mortgage (which I also pay, solely). But it occurs to me that if I overpay, say, 500 on the mortgage now, I might in effect just be gifting my wife 250, if she gets half a year from now.

Should I spend the 500 on hookers and blow instead? Is the kind of advice I'm looking for (and who doesn't want that kind of advice?).

What should I be doing financially and personally so that when the hammer falls, whether I do it or she does, I'm prepped and it's as painless as possible?

PS No kids, so no worries on that score.