Or you could go left leg this year and right leg next year....that's what I do.
Do you plan on adding new birds every year?
I use colors for different crosses, sometimes add a second band for other reasons.
Then make notes so I remember which year is which leg...and what colors might...
I use zipties, but no numbers.
How many birds do you have that you need numbers?
https://www.backyardchickens.com/articles/leg-banding-with-zipties.68075/