Culture starts at the top but ultimately needs to be bought into by your players and parents. A successful culture is one that allows for faster player development while still promoting the enjoyment of the sport.
Coaches all have different personalities but there are some aspects of culture that I believe should permeate every team:
Everything you do should demonstrate your commitment to strong discipline. You should be prompt, you should look the part of a coach, your practice should be organized. You should not tolerate inattentive players. The players must take practice as seriously as a game. There are times for fun and times for intense focus and effort.
You can be a strong disciplinarian and still have players that love you as a coach. The trick is in finding the right time and ways to add fun into your practice. I have always started practice with at least 5 minutes of juggling. During that time players are allowed and encouraged to talk to each other. I also juggle with them and joke around at the same time. With younger players, having the occasional squirt gun practice or ice cream afterwards goes a long way. The minute practice concludes, you’re talking to them (not about soccer) and joking around with them.
I think the best word to describe how I want my players to approach activities in practice and on the ball during games is with creativity. In order to have creativity, players must feel very safe in trying new things and being ok with failure. During a drill a player might come up with a slightly different way to accomplish an objective. I make it a point to stop everything and congratulate the player on taking a chance. Even if it’s counterproductive to the activity. You can at the same time praise them and also let the other players know why you’re focusing them on a different approach. If a player is failing at a drill and getting upset, call it out in a positive way: “Hey, it’s totally fine. Keep trying it. If it was easy we wouldn’t be practicing this. It SHOULD be hard!”
Players will play up or down to the standard you set for them. Do not stand for anything less than 100% effort during practice. You need to call out players who aren’t giving it their all or that attitude spreads quickly. Leverage these techniques as needed.
I’m sure that you could come up with some other great adjectives that describe how you want to run your team. Just give some thought about what you want your team to value then work backwards from there.
For inspiration, I’ve always been really impressed with how Shaun Green runs his sessions and interacts with his players. Spend some time on his youtube channel for a masters class in creating a successful culture.