"Perfect or bust" is a terrible way the live. And often, you wind up going bust.
Two very important principles --
1. Trend upwards: Constantly be improving a little bit and moving in the right direction.
2. Be very, very realistic about where you're at: Seeing things exactly as they are lets you make rapid improvements.
The principle of using "Hard Rules" says that hard rules make life easier. Nailing down extremely precise, unambiguous guidelines on how you're going to do things is easier than having a loose wishful thinking in an area.
So, "I don't eat simple carbohydrates, period, ever" is a very easy rule to follow and explain to others. "I'm trying to eat slightly healthier so, umm, I'll have just one slice of pizza I guess" is a much harder to follow, both personally and with other people.
At the same time, it's ver yimportant to be realistic about where you're at. If you're constantly on the move, don't have a kitchen, and are visiting a city where that will be a difficult dietary rule to follow, you might make one that's slightly random and illogical on the surface but which still keeps the principle up.
I'm in Berlin right now. Here's what I'm running:
"I don't eat simple carbohydrates at all, except for the bread on a donner kebab."
It might seem silly on the surface, but think about it closer -- it means no pastry and no big plate of noodles. It means opting for extra vegetables and no rice. It keeps me away from juice (including the delicious apfelschorle -- apple juice mixed with sparkling mineral water). It means no Turkish pizza, and no grabbing a piece of bread quickly when I'm on the go and I see a bakery.
I know that's a rule I can follow in Berlin, and realistically I'm never going to eat more than two kebabs a day, meaning the equivalent of 2-4 pieces of bread max. That's still more than I'd like, but I know I can follow that rule without going off the rails. Whereas, constantly on the go, "no carbs at all" might not have been realistically possible to follow without setup, prep time, and hassle that I'm unwilling to put in right now.
Imperfect, slightly random hard rules can be great for trending upwards. Quitting soda entirely but continuing to drink sports drinks might seem to be not much of a gain, but it lets you trend upwards, probably cuts your sugar consumption (since you won't always swap a sports drink in for the soda; sometimes you'll grab water or just have no drink), and it puts you in a position to quit or scale back on the sports drinks later. If you've been a hardcore sugar-water-drinkin' person and want to scale back, that might be a hard rule that's easy to follow and gets you trending in the right direction.
Action questions for you:
*What hard rules would you benefit from setting?
*What "perfect or bust ideals" do you have that are holding you back from making smaller improvements? Could you get any benefits from drawing a line in the sand that's not too hard to follow, even one that seems slightly random?