Trying for number #2 pregnancy?? Anyone?

GF
Hi, I have 12 month twin girls. Iam 23 and my husband is 27. I wanted to know how long did you wait to try again? What's a good amount of years? I wanted to try before my husband turned 30. It's alittle diff because I have twins and already have two kids lol. But wondering on how many years everyone waited to try again?:)