You don't have specific targets
Creating a plan without any goals doesn't work that well either. The core purpose of a goal is to give you direction and motivation, and without that, you'll feel like you're just floating around.
A goal should come in the form of weekly, monthly and yearly targets. This will allow you to track your progress better and help you see how far you have to go for you to get that thing you want whether it's a vacation, a new car or just a comfortable emergency savings.
You don't have enough discipline
Discipline can never be left out of the plan when it comes to saving. And if you're discipline hasn't been strong, don't feel bad because this is one of the biggest hurdles that many face.
It will be hard for you to rely on yourself to just set some money aside every month where you can easily access and spend. Have accountability measures like opening an actual account that can automate your saving.
You haven't adjusted your lifestyle
Successful saving requires sacrifice. That means you will need to now separate your necessities from luxuries and the easiest way to do that is budgeting.
With budgets, you will be able to track your spending and align your daily spending with your savings targets. Sacrificing your wants might hurt for a while but, it will be worth it.
You have not left room for fun
Many people don't stay consistent with saving because it makes them feel completely miserable. The idea is that you sacrifice all your enjoyment for a goal that will take years to happen but that's not how it should be.
Within your monthly budget, allocate some money for fun. You shouldn't starve your need to enjoy yourself because that will kill your motivation to save.