He advised caution. ✬

Better to err on the side of caution. ✬

Proceed with caution. ✬

I recommend caution. ✬

I urge caution. ✬

I'd urge caution. ✬

Tom advised caution. ✬

Tom threw caution to the wind. ✬

Tom didn't know how long the leftover chicken had been in the fridge, so he erred on the side of caution and threw it out. ✬

Caution is advised. ✬