Aim for mediocrity not perfection.
This principle might seem counterintuitive at first glance, don't we all want to aim for perfection?
But if you aim for what is the minimum rather than the maximum to still get results you create something much more sustainable for your long term health.
For example, while training 5 times per week might be good, if the minimum needed to get stronger is just once every 7-10 days, you will be far less likely to fail, building 1 training into your routine. You can always add another session into your schedule at a later date, But if you start with 5 sessions then have to drop a couple due to being unsustainable you will feel like you are failing, despite still doing really well.
A second part of this is to look for the next best option, not the perfect option. While a healthy home cooked lunch might be the best option you can have, if you forget to take lunch one morning, what is your next best choice, rather than completely messing up your food for the day. This means the best option available might be a steak pie from a bakery, because you know how many calories are in it, and it will stop you from using McDonald's as an all you can eat buffet. Now I am not saying you should be eating takeout regularly, but we all sleep in occasionally, or forget to buy groceries, so having a second best option for the times where you forget to plan is a great way to ensure you continue to have long term results.
One last way this principle should be implemented in your life is the 90% rule when it comes to nutrition plans. I actively encourage people to take 1-2 meals per week off their nutrition plan. This doesn't mean an all you can eat binge at Pizza Hut, just eat something you like, that isn't in your plan. Because if you eat 3 meals per day, 21 per week, the 905 rule means you can have those 1-2 off and still make good progress. No one got fat from just one meal.