Up to this point in my life, I have purposely tried to avoid using slang and such expressions as you refer to. At middle age, I find my parents' folksy expressions frequently coming to mind, and now, I value them and occasionally make use of them. I thought their usage would paint me as a country bumpkin; now, I see it more as a matter of undeniable heritage! I've also meticulously avoided adopting trendy, current idiom because I thought it often impeded, rather than aided, communication. Anymore I try to let myself use the expressions that I find pleasing and appropriate, instead of considering them all to be out of bounds. Besides, I appreciate such turns of phrase when others are speaking or writing. They add color. And I don't want to be speaking all in bland, neutral beige!
As for expressions I commonly use -- I am scratching my head and will have to get back to you on that!
