How we can influence our minds with positive self belief statements 

We are what we THINK we are. 
This is something that most of us might not contemplate often enough. Who do we think we are and who do we want to be? What self-view do we have? 
As a first step to get to who we want to be is to start thinking of that person. Who are you? Ideally your mind comes up with your values and your strength. But, at this step, negative thoughts might be creeping their way into your mind, holding you back and selling yourself short. Obviously, those aren't helpful. What helps counteract limiting self beliefs are self-affirming statements. Positive statements, e.g. in the form of positive affirmation cards, can act as wonderful reminders for our inner strength.  Those statements are a reflection of what the "higher you" could be thinking and once you start thinking in the patterns that you would be thinking (minus limiting self-belief) this can become a self-fulfilling prophecy in the best of all senses: 
Here are a few positive affirmations  that will always hold, having in mind that you are already thinking like the strong, confident person you want to grow into: 
Positive affirmations for limiting beliefs around skills and abilities: 
"I believe in my abilities and am happy to express my true self."
The reason this statement is so powerful lies in the second part. Being happy to express your true self. Not "faking it" but actually being your true self, just more confident. 
Positive affirmations for fear of failure
"I forgive myself for past mistakes and value the learnings from them."
Forgiving ourselves and accepting that we are human is an underrated skill (whilst many of us are at Olympic levels of beating ourselves up) and reminding ourselves to be grateful for the valuable lessons. No matter what successful person we listen to in an interview. The mistakes they have made and the lessons they have learned are what gets referred to as a stepping stone to success. 
Positive affirmations to counteract a scarcity mindset 
"I celebrate the abundance in my life"
This is one to get your head around. The one resource that we feel is limited in every person's life is time and we all have 24 hours. So where does the time abundance come from? We might have seen time in the wrong perspective in the past. An hour at the dentist getting root canal surgery is maybe not the same as an hour spent at the beach. The beach time will feel like it flies by, in a way that we love. But. you might argue, life is full of root canal days? An abundance mindset will show you that the root canal surgery, whilst uncomfortable and maybe painful, will lead to a better future with less pain. Time spent having an uncomfortable conversation is saving you time of tension going ahead. But there is not only abundance of time, but of everything that is truly needed in your life. 
Positive affirmations around external validation 
"I trust myself and do not solely rely on validation from others."
First of all, we do all need validation from others. We are human beings, highly social and care about others and what they think. That is ok! However, it starts making us feel miserable when we need external validation so much that we can't be true to ourselves because of what the neighbours, friends, [fill in the blank], think. Also, we don't share some of our very personal battles and other people might not even know what is going on inside.  
Knowing that we are enough, how far we have come, given the circumstance is all part of starting to trust ourselves and reminding ourselves of this is truly powerful! 
There are many other affirmations that help our mindset to evolve into a more open, confident and optimistic one. And one day, not too long from now, when we think of who we are, those affirmed positive self beliefs will be just that our positive self beliefs, the old limiting beliefs will be "over-written".