Il en a fait de belles = He played nice tricks (ironic).
Il vous en conte de belles = He is telling you fine tales; He is taking you in finely.
Vous me la donnez (or, baillez) belle (ironic.) = A pretty tale you are telling me; Aren’t you stuffing me up nicely?
Ce que vous proposez est bel et bon, mais je n’en ferai rien = What you propose is all very fine, but I shall do no such thing.
Être dans de beaux draps = To be in a pretty pickle (ironic).
Vous l’avez échappé belle = You have had a narrow escape (or, shave).
Il a beau parler, il ne me convaincra pas = It is of no use for him to speak, he will not convince me; Let him say what he will, he will not convince me.
[The origin of this use of beau is obscure. Larousse suggests the origin may be in the idea of having a fine field for operations, which will be of no value, as our: “it is all very fine for me to speak.”]
Il recommença de plus belle = He began again worse than ever.