Here are some common idioms.
Play your cards right
When you play your cards right, you make the best use of your assets and opportunities.
Put your cards on the table
To put your cards on the table is to state your plans openly.
Sweep something under the carpet
To sweep something under the carpet is to conceal a problem hoping that it will be forgotten.
Put the cart before the horse
To put the cart before the horse is to do things in the wrong order.
Throw caution to the wind
To throw caution to the wind is to act in a reckless way.
On the off chance – just in case
Stand a chance
If you stand a chance, you have a likelihood of success.
Take a chance / take chances
To take a chance is to take risks.
When things change hands, they pass to a different owner.
Change your tune
When you change your tune, you show a very different attitude to something.
Get something off your chest
To get something off your chest is to say something you have wanted to say for a long time.
Keep your cards close to your chest / play your cards close to your chest
To keep your cards close to your chest is to be secretive about your plans.