How would any of you handle this?

Say you replace a old fuse panel to a new breaker panel only to find your wires are now too short to land on the breakers!!! Do you simply make a splice or add a length of wire with a wire nut?

Reason I ask is because I've done jobs behind other folks and have found splices, wire nuts, and even just twisted together with black 33. Scary

How would you handle this?