Hey there. During the time of bot development, I've learnt a lot, there are several things which I wish I could change and several things which I'm glad I did. I wish to share my experience which may help some beginners or even some experts.
Before you reach verification, you must transfer your bot to a team and include a secured alt in the team. Many developers regret not doing it before their application reaches verification. This essentially provides a ray of hope of not losing your bot if you ever lose your main account.
An epic centre is the core of your bot, your bot could be known for it. Take Dyno for example, we all know it for it's moderation capabilities. In a similar way, your bot must be known for something. You need to avoid being a sheep in the flock.
In my opinion advertising can prove out to be effective when you build something unique and let them know your goal behind it along with some visual showcases like a gif. Mentioning commands such as moderation, etc will not attract users, it is at most positive as a add-on of what other things you'll service in your bot.
Top.gg can very well be your best bid to grow your bot. Make sure your bot's short description mentions your features like a keyword which can support it in making an appearance in the search results of the website. Like: https://m.imgur.com/a/qubcb4g
You must not waste your space mentioning 'The only bot you need' or 'The best bot on discord'. One short and meaningful slogan works.
Your bot's name is important. You need to have a name which any other bot is not already occupying to avoid competition and confusion when someone searches for your bot. Take your time deciding your name, you will have it forever.
Votes of your bot on top.gg are very important. The bots appearing in the search results are listed according to their votes. Another important thing is vote credits, top.gg provides you with 15$ credits monthly if your bot gains more than 100 votes. You can use those credits in their auctions to win an advertisement on the website, it's a very effective way to gain servers.