To do the baby sign for okay, simply sign the ASL letters 'O' and 'K' successively.
Alternatively, your thumb and index finger on your dominant hand meet, making a circle, while the remaining fingers point up slightly separated. This is the same sign used by scuba divers to report an "OK" status, and it is also the ASL sign for the letter 'F'.
We mainly use okay to help our babies or toddlers give us status updates regarding their well being.
Use the okay sign, both to affirm and to ask when engaging with your babies. For example, ask them if the clothes you are suggesting are okay, or if they feel okay after tripping. This sign will prove to be useful for many years to come when you are in a social context and need to provide your child with visual affirmation.