Make good choices easy and bad choices hard.

Always keep ready to eat fresh veggies on hand, have healthy meals prepped and frozen to grab and go...

Then don't keep junk food in your house and remove all the apps from your phone and save credit cards from your computer.

Limit the number of times you have to say "no" to unhealthy foods, even if you resist the package of cookies in the cupboard 3 times a day your brain is doing the math that you didn't eat 3 cookies and therefore thinks you can totally have a coke with dinner...

Calorie tracking is a whole different post but it is an absolutely eye opening process when you start.