Back seat driver
The famous air crash that killed the Polish President says that back-seat drivers were a contributing factor in the crash
I don't need any backseat drivers on this project, your advice is just a distraction
While cooking, Evan asked his mom to stop being a back-sear driver
Definition: a passenger in a vehicle who is not controlling the vehicle but who excessively comments on the driver's actions and decisions in an attempt to control the vehicle.
Etymology: This term originated in the United States in the 1920s, when it was first used for a passenger legitimately directing a chauffeur, and it was quickly transferred to figurative use. Some backseat drivers exhibit this type of behavior simply because they feel the driver is taking risks they would not normally take. However, the practice is somewhat dangerous and instead more likely to cause crashes
Test the waters
The Real Estate company are testing the waters with Native advertising to see if it helps them sell houses.
The young scriptwriter tested the waters by getting his friends to read his script before sending it to Hollywood.
Angelia decided to go to a couple of meetings to test the waters before committing
Definition: Try something new
Etymology: based on the literal meaning of test the waters (to put your toe into water to see how cold it is
Knock yourself out
You are going to Spain, Go knock yourself out
You want some of the cookies, Go knock yourself out
You want to ask my cousin out on a date. Go knock yourself out
Definition: Do whatever the hell you want, it doesn't bother me.
Etymology: mid-1900s] Both usages allude to knocking oneself unconscious