Confidence can be gained in various ways, one key area being through our visual senses. You will likely ooze more confidence when wearing your sharpest fit. 

The cut sock trend promotes this idea. Not only do players reap the physical rewards of wearing grip socks, but the confidence you get from their aesthetic plays a significant factor.

Confidence replicates itself on the pitch. A player's risk level trying specific passes, skills, or finishes can often be dictated by their confidence. 

A player without confidence, who usually relies on instinct and muscle memory starts to overthink. Cool-headed strikers snatch at chances or take too many touches when a first-time finish would have sufficed: 

“When you’re going through a bad spell you start to think about what you’re going to do and that can cost you valuable milliseconds,” explains the former Reading, Bolton, and Cardiff City striker Adam le Fondre.

 (Ben Welch)

Tips to build confidence on the pitch:

Having trust in your capabilities drives confidence. Building that trust can be done in a few simple steps. Training with greater intensity mimicking match scenarios can provide live examples that trigger reminders of your capabilities. 

Additionally, identifying your game's strengths early and focusing on them. Whether you're a target man using your physical presence, or a midfield general linking the play with a good touch and crisp pass - focus on your best attributes. 

Ever heard of pre-match superstitions? Players use this routine to generate familiarity and boost confidence. It puts players in a familiar frame of mind making them less affected by external going ons. 

Lastly, an in-game tip I have personally used for years. When the game isn't quite going your way or if you've lost some control/confidence - simplify your next three actions. Getting control back and playing a simple 5-yard pass can build your confidence and help you grow into a game.