Signing that ambiguous contract could become a rod for one's own back if a dispute arose.

A rod for one's own breech lay unused in the attic, a grim relic of old punishments.

When a person walks into the renovated gallery, it's hard to believe one's own eyes.

When people are tempted by flashy projects, it's usually wiser to keep to one's own knitting and build on existing strengths.

Sometimes it's wiser to attend to one's own knitting instead of getting involved in every dispute.

It's often wiser to stick to one's own knitting rather than spread yourself too thin pursuing every new trend.

It's a good idea to tend to one's own knitting before offering advice to others.

Her hoisted with one's own petard scheme collapsed when the evidence she had planted was exposed.

A hoist on one's own petard move by the team cost them the championship.

His scheme, hoisted on one's own petard, spectacularly backfired.