You said that you would discard the 6 of Clubs to say that you want your partner to lead Clubs to you. This is the correct answer. You picked an even card, which is the signal that you want that suit back.

So so summarise the main ways of doing your best in defense situations:

• Lead well and meaningfully, and return partner's lead if it is an encouraging one
• Duck when you know the opposition are trying to lose their losers first
• Signal through discards which suit you want played back, and which you don't want
• Signal through high card play when following a suit, that you want the suit returned.
• Remember the bidding, and mentally decide whose hand the missing cards are likely to be in.
• Take advantage of things like hesitation before play - the person who hesitates is making a decision, so must have a good card they are trying to decide whether or not to play.

As much as you can, try to remember the cards that have already been played, so that you know when a card is a boss.

Now go on to the next lesson, which is on the Stayman Convention.