How can I determine what Pendulum Scale my custom monster should have?

[KingSC912]

*Apologies if this is the wrong place to ask this*

Can someone please explain how Pendulum scales are determined for monsters, I don't want to accidentally make my Cards overpowered.

Thanks in advance.

For reference, here are my custom Pendulum monsters.

[Zamazenta the OS-Tan Fan]

Cool I really like the last card the Mii is something I would really like to see more of when seeing custom Yugioh cards anywho you can pick what ever scales from 0-13 most use 1-12 the ZARC cards use 0-13 but I seen cards with an orginal Pend Scale of 4 to balance themselves and have a pend effect to set their scales to 1 so you can summon Level 1 monsters so lets just say you have to pend scales and there both 4s well you can only summon 4s but if you have a 4 and a 7 you can summon anything from Level 4 to 7 but I would say choose what ever best fits your needs.