i. Excellent communication skills: Okay, let me break it to you so you can understand why this comes first. Communication is only 7% verbal and 93% non-verbal. let's break it further.. The non-verbal part is broken into 55% body language and 38% tone of your voice! what this means is that you can actually pass a message 93 times better without actually saying a damn word! Now it makes sense yeah? No wonder deaf and dumb people can "talk and hear". Learn it, actor!!
ii. Good stage, screen or vocal presence.
iii. The ability to internalize roles and engage the audience.
iv. Good understanding of dramatic techniques
v. Creative insights
vi. Ability to work under pressure
vii. You must be intelligent... everyone can be if they want to.
viii. Strong belief in yourself
ix. You must be confident, dedicated and energetic.
x. The ability to memorize lines

We will add to the list with time and i will be explaining some of these skills in-depth for better understanding... like the internalization of roles and how to do it, voice training and dramatic techniques.
Always check back. Don't forget to drop your comments or questions if you have any.
Best of luck.
Source:
https://vhfilm..com/2019/02/skills-every-good-actor-must-possess.html