Recently I was out riding when my chain began to skip in the big ring due to heavily worn components. The situation worsened surprisingly quickly such that within a few miles I couldn't practically pedal in the big ring (i.e. the force required to keep moving exceeded that which causes the chain to skip over the cogs).
Fortunately, the small ring was less worn so I was able to make it home using that. But it got me wondering whether there are any quick fixes or tricks to overcome a slipping chain, if only temporarily, if this does happen out on a ride.
One thing I tried was to move up/down the rear cassette in the hope that a different tension might alleviate things, but this had little effect.