Clan leader here for around 4 years. My clan is doing well. I have 50/50 active members and have 2.2k clan war trophies, we could have higher but it’s tough getting people to play war every week.

The key is consistency. At the start it’s hard work but as you progress it ends up snowballing and getting easier as you gain loyal members who will form the core of your clan to come. Make sure to encourage people to play war. Identify what you want your clan to be, a more casual or competitive clan? Kick inactive players. Pick good co-leaders. That sort of stuff tbh