Age gap between babies

I was having a discussion with my husband this weekend about us possibly having another baby. Our son is nearly 18 months old, and we both came to a decision that would like to have another baby, and a siblings for him. We both decided that we would ttc early next year.

I just wanted to ask any mums/dads/parents who have 17/18 month olds…

When did you have your next baby?

What are the are gap between your babies?

Any other advice would be appreciated.

Thanks in advance