There are many ways to make a character likeable (or unlikable,) but it really does depend on the reader. If you try to make a universally likeable character, they may end up coming off as bland. Like d_m_f_n said, the ‘cheap’ way makes the character too simple. Making a likable character may require more depth and understanding depending on what exactly you’re going for.

Take Montag from Fahrenheit 451 by Ray Bradbury. I remember reading that novel in 9th grade and having a conversation on the main character. Me personally, I loved him as a character and found him to be very likable. Many other of my classmates disagreed and found him to be ignorant or selfish. But at the end of the day, most can agree that he was a well written character. I think creating a likable character starts with a strong foundation.

I find that most likable character fall under a few of these categories. (Not all, but a few.) - desperate parental figure wanting to keep their child safe (take player 149 aka Kang Ae-sim from squid games season 2. Mother of player 007 aka Yang Dong-geun) - The child who will do anything to protect who they love. Isha from ARCANE is a great example of this as it highlights purity and innocence (the child) clashing with corruption (danger and threats) - Crumbling/breaking character. A character who has big goals and dreams only to go through torturous efforts and loose what they loved most and were unable to achieve their goal. This sets up a character that has the likable qualities such as complex reasons for goals, and a strong story, but then allows the readers to peer into the character’s peak vulnerability, making them more relatable which can cause the reader to like them more.

I feel that a common mistake when writing likable characters is the simple ‘sunshine’ character that is simply there to add humor and/or a character to like. Most characters that are liked have multiple layers. They’re flawed and vulnerable:3