It’s been said many times, but confidence is key.
It’s building it that’s the hard part.
Fortunately, there are quite a few ways to build confidence in small ways.
Kousaka's room is pretty typical for otaku: A complete mess. (Genshiken)
Clean/Organize Your Space
A cluttered space clutters the mind and makes it difficult to think clearly. When you’re unable to think clearly, other aspects of your life tend to suffer. In addition, cleaning up is also a display of competence that you can be inwardly proud of.
Lelouch always keeps his end goal in mind, even if it doesn't look that way. (Code Geass)
Plot Out Your Goals
Write down what you want to have, be, and do. Then list off what it would take to achieve those. Next, list off what steps you can take in the short term to get closer to your goals. Often, you’ll find that those steps are easier to navigate than you thought.
(Otaku no Video)
Watch Something Inspiring
In a way, seeing others make it not only proves it can be done, but gives you “permission” to succeed. It also allows you to study the techniques and mindsets of others and adapt them to help you toward your goals.
Suggestions:
Otaku No Video
Amagami SS
Shirobako
Saekano
Helping others helps Tomoya eventually find himself. (Clannad)
Help Others
Knowing others appreciate you is a good way to build your confidence. In addition, the people you help will also often be willing to help you in return.
After taking up photography, Kazuya's once-average life improves substantially. (Photokano)
Try Something New
Navigate a new hobby, or try something you haven’t tried in a hobby you’re already into. Since you’re inexperienced, you’re going in with no expectations and can watch yourself build competence over time.
(Gunbuster)
Exercise
Exercise clears your head, and the knowledge that you’re doing something good for you can do wonders for your self-esteem.