Answer:
Don't judge a book by its cover
-One shouldn't prejudge the worth or value of something based on its outward appearance alone
Kill two birds with one stone
-Achieve two aims at once/Complete two actions in one
Penny for your thoughts
-A way of asking what someone is thinking
Barking up the wrong tree
-Looking in the wrong place/Accusing the wrong person
Beat around the bush
-Avoiding the main issue/Not speaking directly about the issue