Have the Doctor's mind get scrambled in a temporal-electrical-neuron storm and as a result his conciousness keeps jumping from one personality to another. Or in simple terms: Have the current actor playing The Doctor act in the mannerisms/voices and phrases of past Doctors for the episode. He could even have conversations with himself between different personas. (As 3: "Maybe we should reverse the polarity?") (As 6: "That's a stupid idea.") (As 9: "It could work! It worked once.")
It would be really hard on the actor but I'm sure with enough studying and hard work whoever is the current Doctor could pull it off. With this strategy you wouldn't have to re-cast actors who have passed on or who are too old to resemble their formerselves and it could save money on the budget that could be used towards special effects instead of casting.
It would be really hard on the actor but I'm sure with enough studying and hard work whoever is the current Doctor could pull it off. With this strategy you wouldn't have to re-cast actors who have passed on or who are too old to resemble their formerselves and it could save money on the budget that could be used towards special effects instead of casting.