Consistency is key to people falling in love with your sound, and your productions should reflect this. What makes your sound unique? How would you describe your songs from a music production standpoint? Write that down in your style guide.
Bringing it together
When all of these elements come together, that’s when you create a sonic brand for yourself / your band. Keep that sound consistent, and with time people will start recognizing your sound the moment they hear it.
Variations vs. change
When you deliver the same quality product every single time, fans will be faithful and come back to you for it. After all, it's all about developing loyalty.
Does that mean you can't deviate or expand your musical universe? Of course, you can. However, there's a difference between variation and total change, and it's crucial that you understand it.
If you want to slightly deviate from your regular path and feature ukulele on many songs (which usually isn't part of your sound), then go for it. As long as for the most part the overall sound isn't drastically changing, your fans will probably love the newness. Trying something new is okay.
The more you change your sound, the more you risk losing your audience. Have you ever had a band that you loved their first and second albums, but by the third one they changed their sound, and you no longer liked it? Use that as a cautionary tale. Take side streets, occasionally even make a musical detour, but don't go too far too early as you may risk losing it all.
Now does that mean you can't take risks? Of course, you can. Lady Gaga is known for her roaring synths in a dance style. However, in 2014 she released something of a surprise: the "Cheek To Cheek" album with Tony Bennett. This one was a huge departure from her usual dance style, into the world of swing. Some people loved it, others hated it, but it showed a new side to her. But this change didn't mean that Dance Gaga was gone forever. Her next album "Joanne" returned to what her fans loved most. She was already very well known for dance music before she did something else, so her fanbase was already huge and willing to go along for any journey with her even into temporary swing land.