I think it's more important to think about key areas and what skills are most important. For example, Keys 1-5 and F1-5 are important because they are the easiest to access, and so you should keep all your vital skills there, while debuffing and other less used skills can be further down. I'd suggest clustering several skills by function, and also set up pets so you can just go down the line to debuff when needed.
I've attached my layout if it helps. My Instill is on my alt-F key as it's a skill you turn on and forget.