Regarding handling the downs: That's tough. We usually take a break from the action, spend time with each other and regroup. Generally, we work a lot more on prevention of marriage problems instead of trying to put out fires, though. If we're starting to squabble with each other, it's probably because there's an issue that needs to be addressed, and we need to take the time to work it out.
Our marriage comes first. Having a multi-million dollar exit would be really nice, but it's not going to keep us warm at night.
We have a weekly meeting in which we talk about about relationship stuff, and make sure things are okay on that front. We're a lot more productive when our relationship is working well. It's a good business decision and it makes for a much funner journey.
We've also made a point of taking breaks from the action. Every 3 months or so, we take a road trip for a couple of nights. We both work really hard, so it's helpful to unplug and focus on the relationship every couple of months.
Probably the best marriage advice I could give anyone is to do some preventative marriage counseling. My wife and I made a point of going to marriage counseling the first year after we got married. It's not that our relationship was on the rocks, we just wanted to get it right. So, we spent a year going to a marriage counselor and got a whole bag full of tools to work on our marriage. It's helped us for years, and I'd recommend it to anyone in a serious relationship.
My wife and I are bootstrapping right now.