This was taken from a reply on ask TRP, so I thought I'd share it here as well.

I constantly see newcomers asking how they can build their confidence. Confidence comes in many forms. Being prepared and experienced with a good mindset is a great way to start. An easy way to get the ball rolling in this is to create a poster board with goals you want to achieve, posting that board somewhere you have to see it several times a day, then X each goal out once you achieve it.

Small victories in life are great for this. Setting goals and achieving them build confidence in yourself. Think of things you want to accomplish in life and write them down on a large poster board and put them somewhere you will see them constantly, then as you achieve them, X them out on the poster board so you can see that you accomplished it. Divide the poster board up into 10 sections and write 10 goals on it, and every time you achieve one, you X it out. Then, make a new poster board of goals and leave the old one with the X's on it to see. For instance, If you need to lose weight, set a goal of X amount (pounds or percentage) and write them on the board. Set up weight lifting goals. If you want to learn an instrument, set up X amount of hours per month of practice. X amount of approaches, numbers, etc. Any goal you want, then X them out once you achieve them. It will become a major motivator and the more X's you see, the more confident you will become.

Pretty soon you won't self doubt as much because you will see all of the other small (and large) goals you've achieved staring you in the face.

Putting them in your bedroom in eye sight is a good place for them because it's a constant reminder of things you need to do and things you really wanted to accomplish, being accomplished. I did this when I was learning to do woodworking. I started out with small goals like learning to use different tools, then branched off to learning to build small shelves and what not. It made me motivated to do it more, and it has helped me do something I enjoy with my bare hands. We spend so much time on the damn computer and cell phones that lifting weights and building something with your hands can really be therapeutic. Plus dem bitches love dat manly shiz.

If you're lacking confidence, try a goal board. Starting small is an easy way to get motivated. The more boards you have X'd out, the more confident and fun it becomes.

Just my .02, but it worked for me.