Don't expect great results the first time you try something new

On the contrary, your body and mind are more likely to say 'Sorry I am not used to this' and will try to stop you from doing it. An expert called Dr. Joe Dispenza talks a lot about how our body is actually our unconscious mind and how our daily thoughts condition our personality. This is why developing new habits is so hard. Because our current ways of thinking and doing have been repeated so often that, whether good or bad for us, they have virtually become habits. So, the first time you try something new understand that your body is actually going to see this as an attack on your normal way of doing things and will rather try to stop you.
This is why the ideas in the previous post are so crucial: http://theyouthstand.blogspot.com/2018/10/whatever-you-do-today-good-or-bad.html. Instead, consciously recognise, on a daily basis, that your body is going to try to resist new habits and patterns of thought. Our minds try to make things easy for us by recognising everything we do repeatedly as important and thus making it automatic. This way less mental effort and energy is needed to carry them out. This means for instance, each time you tell yourself you are not capable of doing something or you are not brilliant, you are actually convincing your brain and body to believe this. So next time you try to change and want to feel capable or brilliant, you are going to face a battle with your older self which is going to try to resist this new idea.
So do not expect to have wonderful results the first few days or weeks you try something new. First focus on convincing your body and mind that this is important and that it's going to be the new way of doing things. The way you convince your body is by just repeating it to the point that it says 'Ok, I'm in! This is important'.
So, do not beat yourself up especially in the first few days of trying a new habit or way of thinking. Do not try to do it perfectly or see great results. Just focus on repeating it regularly. As the days roll along your body and mind start believing that you are serious about this and will work with you to make it automatic.
Learn more about how to make important changes in your life here from Dr. Joe Dispenza: https://www.youtube.com/watch?v=La9oLLoI5Rc&t=246s.