now vs yet

[Gilles L]

Dear teacher,
Which one of the following two versions is the best expression to use?

1) Do not make the reservation now
2) Do not make the reservation yet

Thank you

[billmcd]

Dear teacher,
Which one of the following two versions is the best expression to use? It depends on the reason for the statement, but if, for example, you would be waiting for agreement, approval, availability from another party or organization, the typical statement would be as in #2 below.

1) Do not make the reservation now
2) Do not make the reservation yet

Thank you

b.